hairline

noun

hair·​line ˈher-ˈlīn 

1

: a very slender line: such as

a

: a tiny line or crack on a surface

a hairline bone fracture

b

: a fine line connecting thicker strokes in a printed letter

2

: hairbreadth

3

a

: a textile design consisting of lengthwise or crosswise lines usually one thread wide

b

: a fabric with such a design

4

a

: the outline of scalp hair especially on the forehead

b

: the way the hair frames the face

hairline adjective

Synonyms

• inch
• neck
• hair
• step

Examples of hairline in a Sentence

The plate had a hairline running across it.

He has a receding hairline.

Recent Examples on the Web

Open surgery may also be an option, where a surgeon can pinch the aneurysm shut through an incision along the hairline. —Angelica Stabile, FOXNews.com, 25 Oct. 2025

About 50% of women experience a shift in their hair follicles during menopause, including thinning, loss of volume, changes in the hairline, and changes in texture. —Essence, 23 Oct. 2025

Singles for the hairline, doubles just behind, multis where volume helps. —Wyles Daniel, USA Today, 22 Oct. 2025

Between jabs at Notre Dame's independence and weird comments about Freeman's hairline from Franklin, the Irish head coach left the news conference upset. —Jordan Sigler, MSNBC Newsweek, 21 Oct. 2025

Word History

First Known Use

1846, in the meaning defined at sense 1

Rhymes for hairline

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• byline
• canine

Kids Definition

hairline

noun

hair·​line ˈha(ə)r-ˌlīn 

ˈhe(ə)r-

1

a

: a very slender line

b

: a very thin crack on a surface

a hairline bone fracture

2

: the outline of the hair on the head and especially on the forehead

hairline adjective

Medical Definition

hairline

noun

hair·​line -ˈlīn 

: the outline of scalp hair especially on the forehead

hairline adjective