Smarter frame housing shower (8)
I believe the answer is:
brainier
'smarter' is the definition.
(I've seen this before)
'frame housing shower' is the wordplay.
'frame' becomes 'bier' (I have seen 'Funereal frame' mean 'bier' so perhaps 'frame' could also mean 'bier').
'housing' indicates putting letters inside.
'shower' becomes 'rain' (synonyms).
'bier' placed around 'rain' is 'BRAINIER'.
(Other definitions for brainier that I've seen before include "With a higher IQ?" , "smarter" , "More intelligent (colloq.)" , "more clever!" , "appearing brighter" .)