
You know,
Italian housewives have a rule of THUMB:
The Big Bang Theory Season 2, Episode 9

I had lost a lot of THUMB blood.
The Big Bang Theory Season 5, Episode 16

General rule of THUMB,
Game of Thrones Season 7, Episode 3

No. But your THUMB does.
The Big Bang Theory Season 5, Episode 16

so if you broke my right THUMB,
The Big Bang Theory Season 9, Episode 14