Definition from Wiktionary, the free dictionary
nock (plural nocks)
- Either of the two grooves in a bow that hold the bowstring.
- The notch at the rear of an arrow that fits on the bowstring.
- He took his arrow by the nock.
- (nautical) The upper fore corner of a boom sail or trysail.
- Misspelling of knock.
- (transitive) To fit an arrow against the bowstring of a bow or crossbow.
- (transitive) To cut a nock in (usually in an arrow's base or the tips of a bow).