Webster’s Revised Unabridged Dictionary · 1913
Nock
Nock (nŏk), n. [See Notch.] 1. A notch.
He took his arrow by the nock. Chapman.
2. (Naut.) The upper fore corner of a boom sail or of a trysail.
Nock, v. t. To notch; to fit to the string, as an arrow; to string, as a bow. Chapman.