Nominally, he may take a bath (6)
I believe the answer is:
oliver
'may take a bath' is the definition.
I can't judge whether this definition defines the answer.
'nominally he' is the wordplay.
I cannot really understand how this works, but
'he' could be 'iver' and 'iver' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for oliver that I've seen before include "Dickens boy who asked for more, and a musical comedy" , "The boy who wanted more" , "Dickens boy named Twist" , "Dickensian musical" , "Musical from Dickens novel" .)