Casual short robe not only removed... (9)
I believe the answer is:
negligent
'casual' is the definition.
(thesaurus)
'robe not only removed' is the wordplay.
I cannot really understand how this works, but
'robe' could be 'neglige' (neglige is a kind of robe) and 'neglige' is located in the answer.
'not' could be 'nt' (synonyms) and 'nt' is found within the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).
'short' acts as a link.
Can you help me to learn more?
(Other definitions for negligent that I've seen before include "lacking care" , "Lax" , "sloppy" , "Failing to take due care" , "Failing to take proper care" .)