Definition of fifth
1
: one that is number five in a series — see Table of Numbers
2a
: the musical interval embracing five diatonic degrees
c
: the harmonic combination of two tones at this interval
3
: a unit of measure for liquor equal to one fifth of a U.S. gallon (0.757 liter)
4
capitalized
: the Fifth Amendment of the U.S. Constitution
also
: the right accorded by the Fifth Amendment to refuse to testify against oneself
—usually used in the phrase take the Fifth
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Merriam-Webster unabridged
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Time Traveler for fifth
The first known use of fifth was before the 12th century
See more words from the same century