Singer good at darts? (6)

I believe the answer is:

treble

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

'singer' is the definition.
(I know that treble is a type of child soprano)

I can't explain the rest of the clue.

(Other definitions for treble that I've seen before include "High voice; occurring three times" , "Hit in inner ring of dartboard" , "Inner ring score (darts)" , "large measure" , "High boy's singing voice" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app