Clothes, warm, seen unexpectedly (8)
I believe the answer is:
menswear
'clothes' is the definition.
(I've seen this before)
'warm seen unexpectedly' is the wordplay.
'unexpectedly' is an anagram indicator.
'warm'+'seen'='warmseen'
'warmseen' is an anagram of 'MENSWEAR'.
(Other definitions for menswear that I've seen before include "uniform, perhaps" , "Male clothes" , "Sort of clothing" , "it covers their bodies" , "Suits, shirts, ties etc" .)