Quiet spot round sheltered side (6)
I believe the answer is:
sleepy
'quiet' is the definition.
(thesaurus)
'spot round sheltered side' is the wordplay.
'spot' becomes 'spy' ('spy' can be a synonym of 'spot').
'round' means one lot of letters goes inside another.
'sheltered side' becomes 'lee' (I've seen this before**).
'spy' enclosing 'lee' is 'SLEEPY'.
(Other definitions for sleepy that I've seen before include "needing a rest" , "(Of place) low in activity" , "Ready to turn in" , "Dwarf" , "Dozy" .)