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

Israel serves as America’s best friend in the Middle East. —John Devore, Rolling Stone, 20 Mar. 2026

Sage's thirteenth birthday was supposed to be about movies and treats, staying up late with her best friend and watching the sunrise together. —Danielle Parker, CBS News, 20 Mar. 2026

Set in Kyoto, the slasher horror follows three best friends who reunite and rekindle their lifelong friendship during what is intended to be a carefree girls trip. —Andreas Wiseman, Deadline, 20 Mar. 2026

The Tamil-language drama centers on Selvi, a homecare nurse who takes on her best friend Kavitha’s shifts in addition to her own after Kavitha’s sudden collapse. —Naman Ramachandran, Variety, 19 Mar. 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