Considerable area covered by wood (4)
I believe the answer is:
fair
'considerable' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for fair that I've seen before include "All clues should be" , "Favourable" , "Reasonable target?" , "Show - just - lovely" , "promotional exhibition" .)