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Synonyms

best friend

American  
[best frend] / ˈbɛst ˈfrɛnd /

noun

  1. a person’s closest or most cherished friend.

    Sheila has been my best friend since we were seven.
    Synonyms:
    bosom friend, bosom buddy, bff, bf, bestie

  2. something that a person particularly depends on or has a special affection for.

    A purple, stuffed armadillo was my best friend and companion through my whole childhood.

  3. something considered or suggested to be particularly useful or valuable.

    When it comes to saving for retirement, compound interest is your new best friend.

    Your local piano tuner could be your best friend when buying a piano.

Etymology

Origin of best friend

First recorded before 1000

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Berlant plays Maddie’s best friend in the film.

From Los Angeles Times • Apr. 8, 2026

“Instagram can be your best friend as a Realtor,” she adds.

From MarketWatch • Apr. 3, 2026

If she has a tough situation at work, she says, she will mention it to her husband and unpack it with her best friend.

From The Wall Street Journal • Mar. 23, 2026

Brendon played Xander Harris in Buffy the Vampire Slayer over seven seasons between 1997 and 2003 - best friend of the titular character played by Sarah Michelle Gellar.

From BBC • Mar. 21, 2026

I had moved here by choice, after my best friend, Adek, died.

From "Not Nothing" by Gayle Forman

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.