'Fifth' definitions:

Definition of 'fifth'

(from WordNet)
adjective
Coming next after the fourth and just before the sixth in position [syn: fifth, 5th]
noun
A quantity of liquor equal to one fifth of a United States gallon
noun
Position five in a countable series of things; "he was fifth out of several hundred runners"
noun
One part in five equal parts [syn: one-fifth, fifth, fifth part, twenty percent]
noun
The musical interval between one note and another five notes away from it

Definition of 'Fifth'

From: GCIDE
  • Fifth \Fifth\, a. [OE. fifte, fifthe, AS. f[imac]fta. See Five.]
  • 1. Next in order after the fourth; -- the ordinal of five. [1913 Webster]
  • 2. Consisting of one of five equal divisions of a thing. [1913 Webster]
  • Fifth monarchy men (Hist.), a fanatical sect in England, of the time of the commonwealth, who maintained that there would be a fifth universal monarchy, during which Christ would reign on earth a thousand years.
  • Fifth wheel, a horizontal wheel or segment above the fore axle of a carriage and beneath the body, forming an extended support to prevent careening. [1913 Webster]

Definition of 'Fifth'

From: GCIDE
  • Fifth \Fifth\, n.
  • 1. The quotient of a unit divided by five; one of five equal parts; a fifth part. [1913 Webster]
  • 2. (Mus.) The interval of three tones and a semitone, embracing five diatonic degrees of the scale; the dominant of any key. [1913 Webster]

Synonyms of 'fifth'

From: Moby Thesaurus