citharaPronunciation: /ˈsɪθərə, ˈkɪθ-/ (also kithara /ˈkɪθ-/)Definition of cithara noun an ancient Greek and Roman stringed musical instrument similar to the lyre. Origin: late 18th century: Latin, from Greek kithara. Compare with citterncithara in other Oxford dictionaries Definition of cithara in the US English dictionary