Next after the fourth: an ordinal numeral.n. The quotient of unity divided by five; one of five equal parts of anything: as, one fifth (⅕) of an acre.n. In music: A tone five diatonic degrees above or below any given tone.n. The interval between any tone and a tone five degrees distant from it.n. The combination of two tones distant by a fifth.n. In a scale, the fifth tone from the bottom; the dominant: solmizated sol, as G in the scale of C, or E in that of A.n. In early English law, a fifth part of the rents of the year, or of movables, or both, granted or levied by way of tax.