What is the meaning of Fiver?

A banknote with a value of five units of currency.

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).

Source: wiktionary.org