Game ending in draw? (7)
I believe the answer is:
Here is my best explanation:
'game ending in draw?' is the definition.
(a lottery is a prize draw)
'in draw?' is the wordplay.
I cannot really understand how this works, but
'draw?' could be 'lot' (synonyms) and 'lot' is located in the answer.
This may be the basis of clue (or it may be nonsense).
(Other definitions for lottery that I've seen before include "Game in which prizes are awarded by chance", "try his luck here", "Random selection", "Gamble", "A means of raising funds", "Chance event", "Chance competition", "The random drawing of numbers from a drum", "Sweepstake" and "Prize draw".)