Explorer backed by company leaves (7)
I believe the answer is:
tobacco
'leaves' is the definition.
(tobacco leaves)
'explorer backed by company' is the wordplay.
'explorer' becomes 'cabot' (I've seen this before).
'backed' is a reversal indicator.
'by' is a charade indicator (letters next to each other).
'company' becomes 'co' (abbreviation).
'cabot' in reverse letter order is 'tobac'.
'tobac'+'co'='TOBACCO'
(Other definitions for tobacco that I've seen before include "often considered a weed" , "Leaves prepared for smoking" , "New World product" , "Pipe leaves" , "Smokable plant" .)