Rule of thumb

An approximate way of doing something based on presumptions rather than fact. Contrary to popular belief, the idea the law once allowed a husband to beat his wife as long as the device was no thicker than his thumb is false, as such assaults were outlawed for centuries in common law, although the ban wasn't generally codified in written law until the 1980s.

A driver kept going 5 mph over the speed limit, thinking the police had a rule of thumb that it was a waste of time to give out a ticket to anyone going anything lower than that.

by BlastFurnace February 27, 2025

Cum Thumbing

Verb

1. To merge two magazine pages together as one by means of bodily fluids.

"The fact that pages 136 & 137 were stuck together in the Hustler magazine at the sperm bank was an obvious indication that someone had been there cum thumbing it previously."

by billebllunt December 31, 2013

Kentucky Thumb

When you a girl is riding cowgirl and you sneakily put your thumb up her ass.

Brandon: "I gave her the Kentucky Thumb last night"
Cody: "You sick fuck"

by Not Guitarist Ryan May 20, 2021

thumb-ass

when you're so deep in someones ass you no longer have opposable thumbs

bro was so thumb-ass'd he couldnt peel a banana.

by cumslider February 1, 2024

Cat got your thumb?

In Messaging, a subtle inquiry as to whether the other party composes text and thoughts at the same crawl.

This is not a trick question (long pause)... Cat got your thumb?

by Zappin' Nap April 29, 2021

kentucky thumb

When you're getting spicy in the bedroom and your slap rounds hitting her ass just aren't enough.

Come on baby give me that "Kentucky Thumb"!

by cumdiddlediddle May 20, 2021

thumbs up

The ancient phallic symbol of male virility, used today as a means of providing comfort and validation to sentimental wussies.

You did good Michael, thumbs up!

by Masterofnom September 27, 2019