nock
1. nock \'na:k\ n [ME nocke notched tip on the end of a bow; akin to MD nocke summit,] tip, L nux nut - more at NUT 1: one of the notches cut in either of two tips of horn fastened on the end s of a bow or in the bow itself for holding the string 2a: the part of an arrow having a notch for the bowstring 2b: the notch itself 2. nock vt : to make a notch in or fit into or by means of a notch