Out of uniform, alien visitors taking breather inside woods (7)
I believe the answer is:
forests
'woods' is the definition.
('forest' can be a synonym of 'wood')
'out of uniform alien visitors taking breather' is the wordplay.
'out' indicates an anagram.
'uniform alien visitors' becomes 's' (I can't explain this - if you can you should believe this answer much more).
'taking' means one lot of letters goes inside another.
'breather' becomes 'rest' (a breather is a break or rest).
'of' anagrammed gives 'fo'.
'fo'+'s'='fos'
'fos' placed around 'rest' is 'FORESTS'.
'inside' is the link.
Can you help me to learn more?
(Other definitions for forests that I've seen before include "Woodlands" , "Large, densely-wooded area" , "Large woods" , "Densely wooded areas" .)