Inundate in the bathroom? (6)
I believe the answer is:
shower
'inundate' is the definition.
(thesaurus)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for shower that I've seen before include "A brief fall of rain or a cleansing spray" , "Washing facility - worthless lot" , "Incompetent group" , "Lavish" , "Brief spell of precipitation" .)