Webster's Revised Unabridged Dictionary · 1913

Gittern

Gittern (git"tẽrn) , noun

[Old English giterne, Old French guiterne, ultimately from same source as English guitar. See Guitar, and compare Cittern.]

An instrument like a guitar.
Harps, lutes, and giternes. — Chaucer

Gittern , intransitive verb

To play on gittern. — Milton