One demonstrating a bathroom fixture? (6)
I believe the answer is:
shower
I believe this is a double definition.
'one demonstrating' is the first definition.
(somebody showing something)
'a bathroom fixture?' is the second definition.
(something in a bathroom)
(Other definitions for shower that I've seen before include "rain not sounding the same" , "Light rainfall" , "Something depicting" , "Short fall of rain" , "an awful lot" .)