Before end of decider, draw level (4)
I believe the answer is:
tier
'level' is the definition.
('tier' can be a synonym of 'level')
'before end of decider draw' is the wordplay.
'before' means one lot of letters go next to another.
'end of' indicates one should take the final letters.
'draw' becomes 'tie' ('tie' can be a synonym of 'draw').
The final letter of 'decider' is 'r'.
'r' after 'tie' is 'TIER'.
(Other definitions for tier that I've seen before include "Rite about layer" , "Row (of seats)" , "Wedding cake layer" , "Storey" , "I might draw" .)