Gleaner prepared to grow (7)
I believe the answer is:
enlarge
'grow' is the definition.
(I know that enlarge is a kind of grow)
'gleaner prepared' is the wordplay.
'prepared' indicates an anagram.
'gleaner' anagrammed gives 'ENLARGE'.
'to' acts as a link.
(Other definitions for enlarge that I've seen before include "swell?" , "Widen" , "General (anag)" , "Broaden, increase" , "Stretch" .)