Crossword Genius

Classic year incomplete, end of April void (5)

Ross

I believe the answer is:

annul

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

'void' is the definition.
(synonyms)

I don't understand the rest of the clue.

Can you help me to learn more?

(Other definitions for annul that I've seen before include "Cancel or render void" , "Cancel, revoke" , "Countermand" , "Cancel, make void" , "Render invalid" .)

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