nock

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The groove at either end of a bow for holding the bowstring.
• noun The notch in the end of an arrow that fits on the bowstring.
• transitive verb To put a nock in (a bow or arrow).
• transitive verb To fit (an arrow) to a bowstring.

from The Century Dictionary.

• noun A notch; specifically, in archery, the notch on the end of an arrow (or the notched end itself), which rests on the string when shooting, or either of the notches on the horns of the bow where the string is fastened.
• noun In sail-making, the foremost upper corner of boom-sails, and of staysails cut with a square tack.
• noun The fundament; the breech.
• To notch; make a notch in.
• To place the notch of (the shaft or arrow) upon the string ready for shooting.

from the GNU version of the Collaborative International Dictionary of English.

• noun A notch.
• noun (Naut.) The upper fore corner of a boom sail or of a trysail.
• transitive verb To notch; to fit to the string, as an arrow; to string, as a bow.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Either of the two grooves in a bow that hold the bowstring.
• noun The notch at the rear of an arrow that fits on the bowstring.
• noun Common misspelling of knock.
• verb transitive To fit an arrow against the bowstring of a bow or crossbow.
• verb transitive To cut a nock in (usually in an arrow's base or the tips of a bow).

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb make small marks into the surface of