Meaning

noun an impression in a surface (as made by a blow)

noun (British slang) a prison

noun a small cut

originThe noun is derived from Late Middle English nik (“notch, tally; nock of an arrow”). Its further etymology is unknown; a connection with nock (“notch in a bow to hold the bowstring; notch at the rear of an arrow that fits the bowstring; cleft in the buttocks”) has not been clearly established. The verb appears to be derived from the noun, though the available evidence shows that some of the verb…

Etymology from Wiktionary, CC BY-SA 3.0