Polish husband spotted outside (5)
I believe the answer is:
sheen
'polish' is the definition.
(thesaurus)
'husband spotted outside' is the wordplay.
'husband' becomes 'h'.
'spotted' becomes 'seen' (I've seen this before).
'outside' means one lot of letters goes inside another.
'h' going inside 'seen' is 'SHEEN'.
(Other definitions for sheen that I've seen before include "Oil slick" , "actor?" , "Radiance" , "brilliance" , "Glow" .)