Bathe with a girl on the quiet (3)
I believe the answer is:
dip
'bathe with' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'a girl on the quiet' is the wordplay.
'a girl' becomes 'di' (short for Diane or Diana).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'the quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'di'+'p'='DIP'
Can you help me to learn more?
(Other definitions for dip that I've seen before include "A quick bathe" , "Duck" , "Lower into liquid" , "Thick sauce; brief swim" , "Go down" .)