Convenient place to hang the bath plug (2,3)
I believe the answer is:
on tap
'convenient' is the definition.
(thesaurus)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for on tap that I've seen before include "Always available" , "Where to find a washer" , "readily accessible" , "Ready to be drawn off, like beer" , "where C or H is seen?" .)