Put cap on and left one US college (5)

I believe the answer is:

limit

I'm a little stuck... Click here to teach me more about this clue!

'put cap on' is the definition.
I can't tell whether this definition defines the answer.

'left one us college' is the wordplay.
'left' becomes 'l' (common abbreviation).
'one' becomes 'I' (Roman numeral).
'us college' becomes 'MIT' (I've seen this in other clues).
'l'+'i'+'mit'='LIMIT'

'and' acts as a link.

Can you help me to learn more?

(Other definitions for limit that I've seen before include "Put restriction on" , "Confine within bounds" , "verge" , "control" , "Ceiling" .)

I've seen this clue in The Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.