Whisker

whiskers, a beard.
Usually, whiskers. side whiskers.
a single hair of the beard.
Archaic. a mustache.
one of the long, stiff, bristly hairs growing about the mouth of certain animals, as the cat or rat; vibrissa.
Also called whisker boom, whisker pole. Nautical. any spar for extending the clew or clews of a sail so that it can catch more wind.
Radio, Electronics. cat whisker.
Crystallography. a thin filament of a crystal, usually several millimeters long and one to two microns in diameter, having unusually great strength.
by a whisker, by the narrowest margin:
She won the race by a whisker.
Contemporary Examples

What Does a Goatee Say About You? Bryan Curtis November 11, 2009
A GOP Senate? Why It Won’t Come Easy Lloyd Green August 31, 2014

Historical Examples

The Adventures of Harry Richmond, Complete George Meredith
Making People Happy Thompson Buchanan
First Plays A. A. Milne
Stories of a Western Town Octave Thanet
The Silly Syclopedia Noah Lott
End of the Tether Joseph Conrad
Cupid’s Middleman Edward B. Lent
Write It Right Ambrose Bierce

noun
any of the stiff sensory hairs growing on the face of a cat, rat, or other mammal Technical name vibrissa
any of the hairs growing on a person’s face, esp on the cheeks or chin
(pl) a beard or that part of it growing on the sides of the face
(pl) (informal) a moustache
Also called whisker boom, whisker pole. any light spar used for extending the clews of a sail, esp in light airs
(chem) a very fine filamentary crystal having greater strength than the bulk material since it is a single crystal. Such crystals often show unusual electrical properties
a person or thing that whisks
a narrow margin; a small distance: he escaped death by a whisker
n.
see:

by a hair (whisker)
win by a nose (whisker)