[ hair-lahyn ]
/ ˈhɛərˌlaɪn /


a very slender line.
the lower edge of the hair, especially along the upper forehead: a hairline that slowly receded.
worsted fabric woven with very fine lines or stripes.
  1. a very thin line on the face of a type.
  2. a style of type consisting entirely of such lines.
  3. a thin rule for printing fine lines.
  4. undesirable vertical lines between letters, caused by worn matrices.


narrow or fine as a hair: a hairline fracture.

Origin of hairline

First recorded in 1725–35; hair + line1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for hairline

British Dictionary definitions for hairline

/ (ˈhɛəˌlaɪn) /


the natural margin formed by hair on the head
  1. a very narrow line
  2. (as modifier)a hairline crack
  1. a thin stroke in a typeface
  2. any typeface consisting of such strokes
  3. thin lines beside a character, produced by worn or poorly cast type
a rope or line of hair
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for hairline

[ hârlīn′ ]


The outline of the growth of hair on the head, especially across the front.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.