knock one off

1. Make love to yourself
2. A bout of self help
3. To masterbate
4. Pull the popes cap off

Dont go to the shop yet sugar, I just need to quickly knock one off.

by Frank Lard June 06, 2007

knock one off

To have sex or at least reach orgasm in a restricted amount of time.

When I wake up in the morning the gf and me knock one off before I go to work.

by gerf June 04, 2004