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 of hairline

• inch
• hair
• neck
• 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

The direction of each graft, the shape of the hairline and the condition of the donor area can all affect how natural the finished result looks. — Ascend Agency, Chicago Tribune, 6 Nov. 2026

According to the clinic, their surgical model is doctor-led; the doctor who examines the patient draws the plan and the hairline, opens the channels, and stays in the operating room with the team throughout the procedure. — Connie Etemadi, Miami Herald, 3 Nov. 2026

No more missing a hairline movement in the shadows and losing your edge! — Kelsey Fogarty, PC Magazine, 3 Nov. 2026

To ensure a seamless, natural-looking dye job, Monzillo recommends using a little bit of Vaseline on and around your hairline to prevent any color lines from sticking around. — Jennifer Hussein, Allure, 1 Nov. 2026

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
• brucine
• byline

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