best friend

noun

plural best friends

1

: a person's closest and dearest friend

She's my best friend.

We have been best friends since high school.

2

: a person's most desirable or valuable possession or resource

Diamonds may be a girl's best friend, but gold is more affordable.

—William Giese

Lycra-cotton leggings and tunic tops are the pregnant woman's best friend, sartorially speaking.

—Anne Reeks

When cops bang on the door, the toilet is a drug dealer's best friend.

—Frederick Kaufman

Examples of best friend in a Sentence

Recent Examples on the Web

Annotated divorce papers blown up and mounted, interactive exhibits detailing how your mom’s last round of chemo didn’t take, souvenir T-shirts emblazoned with your best friend’s last words before the car crash. — Jill Lepore, New Yorker, 6 Sep. 2026

The couple had their best friends speak at the rehearsal dinner, so on the night itself, all four of their parents spoke. — Liam Hess, Vogue, 4 Sep. 2026

Michigan athletic director Warde Manuel was Vada Murray’s college roommate and best friend. — Mitch Sherman, New York Times, 4 Sep. 2026

One of Eloise’s best friends was their Boston terrier, Ollie, which Tim and Missy brought home after their daughter asked for a puppy two years in a row. — Sam Gillette, PEOPLE, 3 Sep. 2026

Word History

First Known Use

13th century, in the meaning defined at sense 1

Phrases Containing best friend

• man's best friend

Rhymes for best friend

• amend
• append
• ascend
• attend
• backend
• befriend
• boyfriend
• commend
• compend
• contend
• defend
• depend