·adj Consisting of one of five equal divisions of a thing.
II. Fifth ·adj Next in order after the fourth;
— the ordinal of five.
III. Fifth ·noun The quotient of a unit divided by five; one of five equal parts; a fifth part.
IV. Fifth ·noun The interval of three tones and a semitone, embracing five diatonic degrees of the scale; the dominant of any key.