fifth (fĭfth, fĭth)
1. The ordinal number matching the number five in a series.
2. One of five equal parts.
3. One fifth of a gallon or four fifths of a quart of liquor.
a. A tone five degrees above or below a given tone in a diatonic scale.
b. The interval between two such tones.
c. The harmonic combination of two such tones.
d. The dominant of a scale or key.
5. Fifth The Fifth Amendment. Used with the.
[Middle English, from Old English fīfta; see penkwe in the Appendix of Indo-European roots.]
fifth adv. & adj.
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