Oh, derived from the word "ANGEL."
Appropriate.
The Big Bang Theory Season 4, Episode 22
Well... you know how Barry
has the voice of an ANGEL?
The Big Bang Theory Season 11, Episode 17
when you leave him
there sleeping like an ANGEL in his cot.
Money Heist Season 1, Episode 6
...because you're an ANGEL.
The Big Bang Theory Season 8, Episode 9