Monk and rabbi both undressed (5)
I believe the answer is:
abbot
'monk' is the definition.
(an abbot is a senior monk)
'rabbi both undressed' is the wordplay.
'rabbi' becomes 'abb' (I can't justify this - if you can you should believe this answer much more).
'undressed' means to look at the middle letters (the word removes the letters which clothe it).
The middle letters of 'both' are 'ot'.
'abb'+'ot'='ABBOT'
'and' is the link.
Can you help me to learn more?
(Other definitions for abbot that I've seen before include "Prior's clerical superior" , "Supervisor of brothers" , "first in order" , "Head of abbey" , "Religious leader" .)