Ecofriendly (5)
I believe the answer is:
green
'ecofriendly' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for green that I've seen before include "Environmentally concerned" , "one may be putting on" , "Unripe; environmentalist" , "Envious; naive" , "Grassy area; politician" .)