Punishing your significant other by inserting your thumb in her ass without warning. A technique that is crude, but effective. See also, ad hoc.
by Bleeding Blue January 16, 2009

A freakish bird-human hybrid creature baring thumbless, arm-like appendages jutting out in a crooked tangle from her hideous body.
by HorshamNugga March 1, 2009

Mart had to much to drink and couldn’t get aroused. So he didn’t disappoint the lady he used his thumb to help get it up there (thumbing it in).
"Like trying to push a Marshmallow into a piggy bank."
"You’ve got it!"
"Like trying to push a Marshmallow into a piggy bank."
"You’ve got it!"
by scratch_nasty November 2, 2011

when you give the middle finger without holding up your thumb; seen as a rude gesture instead of lighthearted or playful
by PardiB December 9, 2020

by JRhinae August 16, 2016

Tim: good sid what are thou doing to me
Bill: why I'm thumbing you kind sir, it's a hip new way of communication
Bill: why I'm thumbing you kind sir, it's a hip new way of communication
by Cumslut2.0 February 15, 2021

His girlfriend got on hers knees and performed oral sex on him whilst putting her thumb up his bum, she called it thumbing
by Stush69 December 9, 2019
