Occupation that could be habit-forming (10)
I believe the answer is:
dressmaker
'occupation that could' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'habit-forming' is the wordplay.
'habit' becomes 'dress' (I've seen this in another clue).
'forming' becomes 'maker' (I can't justify this - if you can you should give a lot more credence to this answer).
'dress'+'maker'='DRESSMAKER'
'be' acts as a link.
Can you help me to learn more?
(Other definitions for dressmaker that I've seen before include "One producing women's clothing" , "Clothes producer" , "Clothes manufacturer" , "Couturier or seamstress, perhaps" .)