Fiver meaning : A banknote with a value of five units of currency. (by extension) The value in money that this represents. A clenched fist. A mathematical puzzle played on a 5 × 5 grid. A Zaydi Shiite Muslim, who disagrees with the majority of Shiites on the identity of the Fifth Imam. A person who gives five percent of their income or five hours a week of their time to charity (a reduction of ten percent tithing).