From Longman Dictionary of Contemporary Englishfifthfifth1 /fɪfθ/ ●●● S3 W3 adjective 1 coming after four other things in a series in the fifth century her fifth birthday2 → fifth wheel —fifth pronoun I’m planning to leave on the fifth (=the fifth day of the month). —fifthly adverb
Examples from the Corpus
fifth• We came in fifth place in the race.the fifth• Her party is on the fifth.fifthfifth2 noun [countable] 1 HMNone of five equal parts of something2 American EnglishDFD an amount of alcohol equal to 1/5 of an American gallon(1), sold in bottles a fifth of bourbonOrigin fifth1 Old English fifta, from fif “five” 