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 final appearance is still influenced by how the grafts are extracted, how the hairline is designed, the direction in which follicles are placed and how wisely the donor area is used. — Ascend Agency, The Orlando Sentinel, 25 Sep. 2026

Avoid applying too close to the hairline or along the forehead to prevent clogged pores and irritating acne-prone skin. — Emily Hayes, Martha Stewart, 17 Sep. 2026

Johnson really went on a run of clocking this man’s hairline. — Bethy Squires, Vulture, 11 Sep. 2026

The hygienist told me there were hairline fractures along the tops of my teeth. — Literary Hub, 9 Sep. 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