30 Idioms for Best Friend

Idioms are the poetry of everyday language, colorful expressions that allow us to articulate feelings and situations that standard words often fail to capture. They are the bridges we build to understand the landscape of our own lives, especially the profound connection of friendship. 

When trying to define what the best friend means to us, we often reach for these powerful phrases. Is a friend a “rock,” a “partner in crime,” or your “ride or die”? Each idiom offers a different lens, illuminating the unique roles these individuals play.

Exploring these expressions does more than just expand our vocabulary; it inspires deeper thinking about the very nature of friendship, bringing clarity to one of life’s most complex and beautiful relationships. Even best friends have moments where they misinterpret or misunderstand each other. In such situations, using lighthearted expressions from the list of idioms for being confused can help ease the tension and add humor to the confusion.

Idioms for Best Friend

Here are 30 common idioms and slang terms used to describe the best friend. Each entry includes a meaning, an example sentence, and alternative phrases.

1. Partner in Crime

• Meaning: A friend with whom you have fun and share adventures; someone who is always on your side, especially when bending the rules.
• Use in a sentence: From planning surprise parties to trying crazy new recipes, Sarah has always been my partner in crime.
• Other ways to say it: My ride or die, my wingman/wingwoman, my accomplice.

2. BFF (Best Friends Forever)

• Meaning: A very common acronym used as urban slang for the best friend, signifying a deep and lasting friendship. It defines the best friend in the most direct way.
• Use in a sentence: I can’t wait to see my BFF this weekend; we’ve been friends since kindergarten.
• Other ways to say it: Bestie, best bud, the best mate.

3. Thick as Thieves

• Meaning: To be extremely close friends who share secrets and are often seen together.
• Use in a sentence: Those two have been thick as thieves ever since they met last year.
• Other ways to say it: Inseparable, two peas in a pod, joined at the hip.

4. My Rock

• Meaning: The best friend who is exceptionally reliable, supportive, and strong for you, especially during difficult times.
• Use in a sentence: When I was going through a tough time, my best friend was my rock.
• Other ways to say it: My anchor, my support system, my foundation.

5. Ride or Die

• Meaning: (Modern slang) A person who is fiercely loyal and will support you through any situation, no matter how difficult. This is a powerful slang term for the best friend.
• Use in a sentence: He is my ride or die; I know he’d do anything for me, and I’d do the same for him.
• Other ways to say it: Unconditionally loyal, always has my back, a friend through thick and thin.

6. Two Peas in a Pod

• Meaning: Two people who are very similar in interests and character, making them natural best friends.
• Use in a sentence: They both love hiking and old movies; they’re truly two peas in a pod.
• Other ways to say it: Cut from the same cloth, kindred spirits, like-minded.

7. Joined at the Hip

• Meaning: A cute saying for two people who are always together and seem inseparable.
• Use in a sentence: In high school, we were joined at the hip; you never saw one of us without the other.
• Other ways to say it: Inseparable, always together, attached at the hip.

8. Bosom Buddy

• Meaning: A very close, intimate friend. The term “bosom” refers to the chest, implying a friendship held close to the heart.
• Use in a sentence: My grandmother and her neighbor have been bosom buddies for over fifty years.
• Other ways to say it: Dearest friend, confidante, close companion.

9. My Person

• Meaning: (Popularized by the show Grey’s Anatomy) The one person you can always count on, who understands you completely. This defines the best friend who is your ultimate emotional support.
• Use in a sentence: No matter what happens, I know I can always call you because you’re my person.
• Other ways to say it: My go-to person, my number one, my anchor.

10. Bestie / Bestie for the Rest

• Meaning: A cute, common slang word for the best friend. “Bestie for the rest” is a playful extension meaning you’ll be friends for life.
• Use in a sentence: I’m having brunch with my bestie on Saturday.
• Other ways to say it: BFF, best bud, main squeeze (platonic).

11. A Friend Through Thick and Thin

• Meaning: A loyal friend who supports you during both good times (thick) and bad times (thin). This phrase defines the difference between a friend and the best friend.
• Use in a sentence: He proved he was a friend through thick and thin when he helped me move in the pouring rain.
• Other ways to say it: A true friend, a loyal companion, my ride or die.

12. Know Someone Inside Out

• Meaning: To know someone extremely well, including their habits, feelings, and secrets.
• Use in a sentence: Of course, I knew she’d love that gift; I know her inside out.
• Other ways to say it: Know someone like the back of your hand, read someone like a book.

13. My Other Half

• Meaning: A friend who complements you so perfectly that they feel like a part of you.
• Use in a sentence: We think so much alike; she’s truly my other half.
• Other ways to say it: My soulmate (platonic), my kindred spirit, my twin.

14. My Day One

• Meaning: (Slang) A friend you have known for a very long time, since the beginning of a certain phase of your life or from the very start.
• Use in a sentence: We met in first grade, so she’s my true day one.
• Other ways to say it: Childhood friend, longtime friend.

15. On the Same Wavelength

• Meaning: To understand each other’s feelings and thoughts, often without needing to speak.
• Use in a sentence: We’re always on the same wavelength; I was just about to suggest we get pizza!
• Other ways to say it: In sync, think alike, get each other.

16. My Go-To

• Meaning: The person you turn to first for advice, support, or a good time. A synonym for your closest friend.
• Use in a sentence: Whenever I have a problem, she’s my go-to for advice.
• Other ways to say it: My first call, my confidante, my person.

17. Fast Friends

• Meaning: People who become close friends very quickly after meeting.
• Use in a sentence: We only met a month ago, but we became fast friends over our shared love for sci-fi.
• Other ways to say it: Hit it off immediately, clicked right away.

18. Brother/Sister from Another Mother/Mister

• Meaning: (Slang) A friend who feels as close as a sibling.
• Use in a sentence: David and I have been friends for so long, he’s my brother from another mother.
• Other ways to say it: My chosen family, like a brother/sister to me.

19. My Confidante

• Meaning: A person with whom you share private matters or secrets, trusting them not to repeat it.
• Use in a sentence: He is more than a friend; he is my trusted confidante.
• Other ways to say it: My secret-keeper, my sounding board.

20. My Anchor

• Meaning: A friend who keeps you grounded and provides stability in your life, especially when you feel lost.
• Use in a sentence: During that chaotic year, her steady advice was my anchor.
• Other ways to say it: My rock, my support.

21. My Main

• Meaning: (Slang) Your primary, most important friend.
• Use in a sentence: I’m going to the concert with my main.
• Other ways to say it: My number one, my go-to, my bestie.

22. My Ace

• Meaning: (Slang) Your best friend, someone you can rely on.
• Use in a sentence: Don’t worry, my ace will be here soon to help us out.
• Other ways to say it: My right-hand man, my main.

23. My Home

• Meaning: (Urban slang) A close friend from your neighborhood or someone you’re very comfortable with.
• Use in a sentence: I’m just chilling with my homes this weekend.
• Other ways to say it: My bud, my pal, my crew.

24. My People

• Meaning: The group of friends you feel you truly belong with; your tribe. Your best friend is the leader of this group.
• Use in a sentence: I can’t wait for the holidays so I can just relax and be with my people.
• Other ways to say it: My tribe, my crew, my inner circle.

25. My Sounding Board

• Meaning: A friend you trust to listen to your ideas and give you honest feedback.
• Use in a sentence: Before I make any big decisions, I always talk to my best friend—she’s my sounding board.
• Other ways to say it: My advisor, my confidante.

26. My Cheerleader

• Meaning: A friend who always supports you, encourages you, and celebrates your successes.
• Use in a sentence: Even when I doubted myself, my best friend was my biggest cheerleader.
• Other ways to say it: My biggest fan, my supporter.

27. A Shoulder to Cry On

• Meaning: Someone who listens sympathetically to your problems and offers comfort.
• Use in a sentence: After the breakup, I was so grateful to have her as a shoulder to cry on.
• Other ways to say it: A good listener, a comforter.

28. My Human Diary

• Meaning: (Modern slang) THE best friend you can tell absolutely anything to, knowing they will keep your secrets safe.
• Use in a sentence: I don’t need to write things down; my bestie is my human diary.
• Other ways to say it: My secret-keeper, my confidante.

29. My Chosen Family

• Meaning: Friends who are so close that they are considered family members by choice, not by blood.
• Use in a sentence: We always spend the holidays together; they’re my chosen family.
• Other ways to say it: My people, my tribe.

30. Kindred Spirit

• Meaning: A person whose interests, attitudes, and soul seem to align perfectly with your own.
• Use in a sentence: From the moment we talked about our favorite books, I knew I had found a kindred spirit.
• Other ways to say it: Soulmate (platonic), my other half, two peas in a pod.

Fill-in-the-Blank Exercise

Complete each sentence with the most appropriate idiom or slang term for a best friend from the list.

1. When I lost my job, she was __________________, keeping me positive and focused.
2. We have been __________________ since the first day of college; we’re always together.
3. He’s my __________________; I know he’ll back me up no matter what.
4. They finish each other’s sentences; they are completely on the __________________.
5. I can tell her anything because she’s my trusted __________________.
6. My best friend is my biggest __________________, always cheering me on from the sidelines.
7. We met on vacation last year and became __________________ almost instantly.
8. I don’t know what I’d do without you; you’re __________________.
9. He’s more than a friend; he’s my __________________ from another mother.
10. They have been __________________ for years, sharing all of their secrets.
11. Whenever I need to vent, I’m so grateful to have a __________________.
12. She has supported me through good times and bad; she is a true friend __________________.
13. From late-night study sessions to road trips, you’ve always been my __________________.
14. They love all the same weird movies and music; they are truly __________________.
15. I don’t need to explain myself to her; she __________________ me inside out.

Answer Key

1. my rock / my anchor
2. joined at the hip
3. ride or die / ace
4. same wavelength
5. confidante / human diary
6. cheerleader
7. fast friends
8. my person
9. brother
10. thick as thieves
11. shoulder to cry on
12. through thick and thin
13. partner in crime
14. two peas in a pod / kindred spirits
15. Knows

Conclusion

The rich collection of idioms for friendship highlights its many facets—loyalty, fun, support, and an almost telepathic understanding. Using these phrases does more it then makes our language more vibrant; it helps us define the roles these crucial people play in our lives. 

Actively listening to these idioms and practicing their use can significantly enhance our communication skills. More importantly, it fosters a higher degree of emotional intelligence, allowing us to articulate our appreciation for our closest friends and to better understand the complex, beautiful, and essential nature of human connection.