It's probably a EUPHEMISM
for urination.
The Big Bang Theory Season 5, Episode 12
...which I think we all know
is a popular EUPHEMISM...
The Big Bang Theory Season 3, Episode 7
I'm gonna guess
that's not a EUPHEMISM.
The Big Bang Theory Season 11, Episode 11
Oh. A clever, albeit obsolete, EUPHEMISM
for insufficient blood flow...
The Big Bang Theory Season 3, Episode 2