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

The two best friends took opposite approaches to their Loewe show looks. — Hannah Jackson, Vogue, 3 Oct. 2026

Using genetic genealogy, the investigators determined the DNA was that of Frederick Tanzer, a doctor who in 1989 was the husband of Beatty’s best friend. — Tim Stelloh, NBC news, 2 Oct. 2026

After his best friend died of AIDS, activist Cleve Jones channeled his grief into a sewing project that became the AIDS Memorial Quilt. — René Ostberg, Encyclopedia Britannica, 2 Oct. 2026

In fact, the book’s depiction of Nick’s friendship and burgeoning relationship with Daisy’s golf-loving best friend Jordan Baker is upgraded to a torrid romance with its own love song and bedroom scenes that match Daisy’s and Gatsby’s. — Christopher Arnott, Hartford Courant, 1 Oct. 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