How is “under the weather” used?

In The Gentlemen (2020), one line is: “Now, I can see you're feeling somewhat under the weather.”

Which movie is “under the weather” from?

The clip at the top of this page is from The Gentlemen (2020).

if you are or feel under the weather, you feel slightly ill / sick and not as well as usual

informal · Heard in 4 moviesPlay Idioms

Oxford100% of films
if you are or feel under the weather, you feel slightly ill / sick and not as well as usual
She's a bit under the weather this afternoon.
Hey, uh, my boys are feeling a little under the weather, Al.

Definitions from the Oxford Advanced Learner's Dictionary, 9th edition

Now, I can see you're feeling somewhat under the weather.

Said in 8 films · #1