"of the Goths," Germanic people who lived in Eastern Europe c.100 C.E., "pertaining to the Goths or their language," 1610s, from Late Latin Gothicus, from Gothi, Greek Gothoi, all from Gothic gutþiuda "Gothic people," the first element cognate with Old Norse gotar "men." "The sense 'men' is usually taken to be the secondary one, but as the etymology of the word is unknown, this is uncertain" [Gordon]. The unhistorical -th- in English is from Late Latin.
Used in sense of "savage despoiler" (1660s) in reference to their fifth-century sacking of Roman cities (cf. vandal, and French gothique, still with a sense of "barbarous, rude, cruel"). Gothic also was used by scholars to mean "Germanic, Teutonic" (1640s), hence its evolution as a 17c. term for the art style that emerged in northern Europe in the Middle Ages, and the early 19c. literary style that used northern European medieval settings to suggest horror and mystery. The word was revived 1983 as the name for a style of music and the associated youth culture; abbreviated form goth is attested from 1986. Gothic revival in reference to architecture and decorating first recorded 1869 in writing of C.L. Eastlake.