Make it possible to be lean, perhaps (6)
I believe the answer is:
enable
'make it possible' is the definition.
(I've seen this before)
'be lean perhaps' is the wordplay.
'perhaps' indicates an anagram.
'be'+'lean'='belean'
'belean' anagrammed gives 'ENABLE'.
'to' acts as a link.
(Other definitions for enable that I've seen before include "Capacitate" , "Provide with means or opportunity" , "Activate" , "Make possible using baleen" , "Give power or capacity to" .)