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

Graft count, hairline work and beard procedures A patient requesting 5,000 grafts may not need that many, and the donor area may not have enough hair available to support the procedure. — Kaitlyn Gomez, Miami Herald, 16 Oct. 2026

Polished pixie For the woman who has nothing to hide (like, not even some hairline acne), a pixie has always been a power move. — Loren Savini, Allure, 14 Oct. 2026

In my case, and most commonly, gray hair appears at the temples and hairline. — Ellie Davis, Vogue, 8 Oct. 2026

Three to five days after symptoms start, patients may experience a rash, first appearing on the face at the hairline before moving downwards to the neck, chest, stomach, arms, legs and feet. — ABC News, 6 Oct. 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