Obsolete form of fifteen.

(slang) A banknote with a value of five units of currency. / (slang, by extension) The value in money that this represents. / (colloquial) A clenched fist. / A mathematical puzzle played on a 5 × 5 grid.

plural of fiver

(humorous) A large forehead.

(Islam) A Zaidi Shi'a Muslim. / (fandom slang) A fan of the American science-fiction television series Babylon 5.

plural of Fiver

plural of nine-to-fiver

A surname.

plural of fiveling

Cinquefoil.