The forward upper end of a sail that sets with a boom. Also, a term used for notch.
·noun A <<Notch>>. II. Nock ·noun The upper fore corner of a boom sail or of a trysail. III. Nock ...
Webster's Dictionary of the English Language
The breech; from NOCK, a notch. ...
Dictionary of The Vulgar Tongue by Francis Grose
slender, pliable. Lane. ...
A glossary of provincial and local words used in England by Francis Grose