Show one knows

I think it could be either:

Which length description are you looking for?:

3,2

let on

(Other definitions for let on that I've seen before include "Divulge (secret to)" , "Reveal, divulge" , "Reveal information" , "Spill the beans" , "Tell me" .)

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.