One line of a popular chorus (3)

I believe the answer is:

arc

'one line' is the definition.
(arc is a kind of line)

'of a popular chorus' is the wordplay.
'of' indicates a hidden word.
'ARC' is hidden within 'popular chorus'.

(Other definitions for arc that I've seen before include "Curved section" , "Curving trajectory" , "Curvature" , "Car (anag.)" , "A curve for Joan of . . ." .)

I've seen this clue in the Evening Standard.

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.