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

Keep scrolling to start the season strong with ’90s-but-better jelly mules, cute lightweight dresses, and a sling bag that’s about to become your water bottle’s new best friend. —Annie Blackman, InStyle, 6 June 2026

On the limited series, based on Araminta Hall’s 2020 novel of the same name, Washington plays Eleanor, a successful CEO whose life is upended when one of her best friends is murdered. —Kate Aurthur, Variety, 6 June 2026

One German shell exploded above where Raymond Bolduc, Picard’s best friend, was sheltering. —Kevin Maurer, The Atlantic, 6 June 2026

Nikki was attending the festival with her best friend from college, Lori Nelson, who had traveled to Healdsburg from Nevada. —Liz Thach, Forbes.com, 6 June 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