Level but empty timer (4)
I believe the answer is:
tier
'level' is the definition.
(I know that level can be written as tier)
'empty timer' is the wordplay.
'empty' means to remove the middle letters.
'timer' with its centre taken out is 'TIER'.
'but' acts as a link.
(Other definitions for tier that I've seen before include "Plague" , "'Level, grade (4)'" , "Row, level" , "range" , "band" .)