Crossword Genius

Age immediately following prohibition era in US (6-3)

Ross

I believe the answer is:

twenty-one

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

'age immediately following prohibition era' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

'us' is the wordplay.
I cannot quite understand how this works, but
'us' could be 'we' and 'we' is located in the answer.
This explanation may well be incorrect...

'in' acts as a link.

Can you help me to learn more?

(Other definitions for twenty-one that I've seen before include "Card game, blackjack or pontoon" , "XXI - used to be the coming of age year" , "Target total in blackjack or pontoon" .)

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.