FIFTH, adjective [See Five.] 1. The ordinal of five; the next to the fourth. 2. Elliptically, a fifth part; or the word may be considered as a noun, as to give a fifth or two fifths. FIFTH, noun In music, an interval consisting of three tones and a semitone.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI