hairline

n.	1.	a very thin line.
	2.	the natural margin formed by hair on the head, especially the edge of growth of hair on the forehead; as, a receding hairline.

Noun	1.	hairline - a very thin line
	2.	hairline - the natural margin formed by hair on the head

band, bar, cross-hatching, dash, delicacy, delicate, delicate distinction, delineation, diagonal, differentia, differential, distinction, dotted line, fine point, finespun, hachure, hairsplitting, hatching, line, lineation, margin, narrow margin, nice, nice distinction, nicety, nuance, particle of difference, point of difference, refined, refinement, score, shade of difference, slash, streak, streaking, striation, strip, stripe, striping, stroke, sublineation, subtle, subtle distinction, subtlety, underline, underlining, underscore, underscoring, virgule, wide margin