Started the fire and left it (3)
I believe the answer is:
lit
'started the fire' is the definition.
(I've seen this in another clue)
'left it' is the wordplay.
'left' becomes 'l' (common abbreviation).
'l'+'it'='LIT'
'and' acts as a link.
(Other definitions for lit that I've seen before include "landed here" , "Burning" , "was illuminating" , "Set afire" , "Set alight" .)