Green area, but less than leafy (3)
I believe the answer is:
lea
'green area' is the definition.
'lea' can be an answer for 'area' (lea is a kind of area). I'm not sure about the 'green' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lea that I've seen before include "Open pasture" , "'The lowing herd wind slowly o'er the . . .'" , "grazing area" , "Field" , "River of east London" .)