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

Many of the people in the old footage — David’s best friend’s wife and children — were murdered during the Hamas assault. —Miami Herald, 23 Jan. 2026

Oracle cofounder Larry Ellison often described Jobs as his best friend. —Preston Fore, Fortune, 23 Jan. 2026

And if an actual trip isn’t in the cards right now, click on the tropical Open Doors links below to take some virtual journeys—your celeb best friends have invited you for a visit. —Michael Gioia, Architectural Digest, 23 Jan. 2026

If Bancroft was the love of Brooks’ life, then Carl Reiner was his best friend, and losing them both — 15 years apart — would be enough to topple a lesser man, as well as his documentary. —Ben Travers, IndieWire, 22 Jan. 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