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

• ace
• hair
• hairbreadth
• hairsbreadth
• hop, skip, and jump
• inch
• neck
• shouting distance
• step
• stone's throw

Examples of hairline in a Sentence

The plate had a hairline running across it.

He has a receding hairline.

Recent Examples on the Web

Achieving Natural Results Properly performed hair transplants are crucial for achieving a balanced hairline and even growth. —William Jones, USA TODAY, 1 Feb. 2025

Later on in the week, the first appearance of a hairline sliver of a crescent moon appearing low in our western twilight sky is a sky signal by which the ancients set their calendars. —Joe Rao, Space.com, 31 Jan. 2025

The shot was fairly close to her hairline, and her hair could have dislodged soot. —Ariane Lange, Sacramento Bee, 26 Jan. 2025

Consistent use revealed early signs of new hair growth along the hairline — a promising indicator of its effectiveness — though noticeable thickening and regrowth can take up to six months. —Jennifer Ford, People.com, 9 Jan. 2025

Word History

First Known Use

1846, in the meaning defined at sense 1

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