Boat off, head of consolidating company leaves (7)
I believe the answer is:
tobacco
'leaves' is the definition.
(tobacco leaves)
'boat off head of consolidating company' is the wordplay.
'off' indicates an anagram.
'head of' indicates taking the first letters.
'company' becomes 'co' (abbreviation).
The initial letter of 'consolidating' is 'c'.
'boat' with letters rearranged gives 'toba'.
'toba'+'c'+'co'='TOBACCO'
(Other definitions for tobacco that I've seen before include "Leaves prepared for smoking" , "Smokable plant" , "Addictive substance" , "(Treated leaves of) American plant" , "often considered a weed" .)