sub Definition

sub (colloq)
noun

1. A submarine.
2. A substitute player.
3. A small loan; an advance payment, eg from someone's wages to help them subsist.
4. A subeditor.
5. A subscription fee.

Form: subs (usually)
6. A subaltern.

verb subbed, subbing

intr
1. To act as a substitute.
tr & intr
2. To subedit or work as a subeditor.
3. To lend (especially a small amount of money)

Example: Can you sub me a quid till tomorrow?

Etymology: 17c.