Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun hairline

2 senses of hairline

Sense 1
hairline -- (a very thin line)
       => line -- (a mark that is long relative to its width; "He drew a line on the chart")

Sense 2
hairline -- (the natural margin formed by hair on the head)
       => boundary, bound, bounds -- (the line or plane indicating the limit or extent of something)