fifth

(noun) a quantity of liquor equal to one fifth of a United States gallon.

(noun) position five in a countable series of things. Example: "He was fifth out of several hundred runners."

(noun) one part in five equal parts. Synonyms: one-fifth, fifth part, twenty percent.

(noun) the musical interval between one note and another five notes away from it.

(adj) coming next after the fourth and just before the sixth in position. Synonyms: 5th.