Crossword Genius

Busy, possibly on radio (6)

Ross

I believe the answer is:

active

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

'busy' is the definition.
(similar in meaning)

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for active that I've seen before include "Not passive" , "Engaged, not idle" , "Vigorously moving" , "Moving frequently" , "Keeping busy or operative" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app