n.1. a. whiskers The hair on a man's cheeks and chin.
b. A single hair of a beard or mustache.
2. One of the long stiff tactile bristles or hairs that grow near the mouth and elsewhere on the head of most mammals; a vibrissa.
3. Informal A narrow margin; a hairsbreadth: The candidate lost the election by a whisker.
4. Nautical One of two spars or booms projecting from the side of a bowsprit for spreading the jib or flying-jib guys.
5. Chemistry An extremely fine filamentary crystal with extraordinary tensile strength and unusual electrical or surface properties.