Suit damaged in extra small amounts of liquid (8)
I believe the answer is:
moisture
'small amounts of liquid' is the definition.
'suit damaged in extra' is the wordplay.
'damaged' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'extra' becomes 'more' (I've seen this before).
'suit' is an anagram of 'istu'.
'istu' placed inside 'more' is 'MOISTURE'.
(Other definitions for moisture that I've seen before include "Small amount of liquid that causes dampness" , "Liquid in vapour or spray form" , "Slight wetness" , "Small amount of liquid causing dampness" , "Liquid, in drops perhaps" .)