1. hairline(n = noun.communication) - a very thin line;
is a kind of line
has particulars: hair stroke
2. hairline(n = noun.body) - the natural margin formed by hair on the head;
is a kind of bound, boundary, bounds
is a part of hair
has parts: widow's peak
1. a very thin line. [WordNet 1.5]
2. the natural margin formed by hair on the head, especially the edge of growth of hair on the forehead; as, a receding hairline. [WordNet 1.5]
hairline, n.
1 the edge of a person's hair, esp. on the forehead.
2 a very thin line or crack etc.