Etymology
Advertisement

hairline (n.)

also hair-line, "cord made of hair," 1731, from hair + line (n.). Meaning "a very fine line" is from 1846. As "the outline of the hair on top of the head," by 1903. As an adjective, of cracks, etc., 1904.

Advertisement
Advertisement
Definitions of hairline

hairline (n.)
a very thin line;
hairline (n.)
the natural margin formed by hair on the head;
From wordnet.princeton.edu