Where does “cithera” come from?

cithera (Vulgar Latin) comes from Latin cithara, from Ancient Greek κιθάρα — lyre; the ribs of the horse; ivy.

Ancestry of “cithera”, step by step

Step	Language	Word	Meaning
1	Latin	cithara	cithara, lyre, lute, guitar; guitar
2	Ancient Greek	κιθάρα	lyre; the ribs of the horse; ivy