Pear-shaped fruit: dull greenish colour (7)
I believe the answer is:
avocado
This clue is a double definition.
'pear-shaped fruit' is the first definition.
(I've seen this before)
'dull greenish colour' is the second definition.
(I've seen this before)
(Other definitions for avocado that I've seen before include "Savoury pear-shaped fruit" , "Are mostly outspoken party getting" , "Dark green pear-shaped fruit" , "Alligator pear" , "A posh tropical pear" .)