Merriam-Webster's Collegiate® Dictionary, 11th Edition
NAIL
I. noun
Etymology: Middle English, from Old English nægl; akin to Old High German nagal nail, fingernail, Latin unguis fingernail, toenail, claw, Greek onyx Date: before 12th century
1. a horny sheath protecting the upper end of each finger and toe of humans and most other primates, a structure (as a claw) that terminates a digit and corresponds to a nail, a slender usually pointed and headed fastener designed to be pounded in,
II. transitive verb Date: before 12th century to fasten with or as if with a nail, to fix in steady attention ,
3. catch , trap , to expose usually so as to discredit , to arrest or punish for an offense,
4. strike , hit , to put out (a runner) in baseball, to perform or complete perfectly or impressively , to gain or win decisively, to settle, establish, or represent clearly and unmistakably, to copulate with, nailer noun