Top Definition
The act of forcing ones thumb into a partners rectal passage, without the act being discussed or pre arranged.

There is a high chance that this act is will be made by a opportunist and stealthily approached.
"Hey Pash whats that over there?"
"oooooh my god what the fuck was that?"
"i just thrum boned you dude!!!"
by Titanium Ukrainian December 14, 2007
Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.