cithern vs cittern

cithern and cittern both are nouns.

Word	Noun	Adjective	Verb	Adverb
cithern	Yes	No	No	No
cittern	Yes	No	No	No

As nouns, cithern and cittern are synonyms defined as:

cithern and cittern: a 16th century musical instrument resembling a guitar with a pear-shaped soundbox and wire strings

Other synonyms of cithern include cither, citole, gittern.

cithern (noun)	cittern (noun)
a 16th century musical instrument resembling a guitar with a pear-shaped soundbox and wire strings	a 16th century musical instrument resembling a guitar with a pear-shaped soundbox and wire strings