It's proof of CONCEPT.
The Big Bang Theory Season 9, Episode 24
I find the CONCEPT of coitus ridiculous
The Big Bang Theory Season 6, Episode 20
Do you understand
the CONCEPT of blackmail?
The Big Bang Theory Season 1, Episode 16
I didn't really understand
the CONCEPT of death, the finality of it.
Game of Thrones Season 2, Episode 9
You must have heard
of that CONCEPT, haven’t you, miss?
Money Heist Season 1, Episode 11