Damp watery vapour nothing contained (5)
I believe the answer is:
moist
'damp' is the definition.
(synonyms)
'watery vapour nothing contained' is the wordplay.
'watery vapour' becomes 'mist' (I've seen this before).
'nothing' becomes 'O' (looks like zero - 0).
'contained' is an insertion indicator.
'mist' enclosing 'o' is 'MOIST'.
(Other definitions for moist that I've seen before include "bit wet" , "Dampish" , "Affected by tears, perhaps" , "Damp, humid" , "Damp or clammy" .)