This protective garment superior to the rest? (7)
I believe the answer is:
overall
'this protective garment' is the definition.
(overall is a kind of protective garment)
'superior to the rest?' is the wordplay.
'superior to' becomes 'over' (I've seen this in another clue).
'the rest?' becomes 'all' (I can't explain this - if you can you should give a lot more credence to this answer).
'over'+'all'='OVERALL'
(Other definitions for overall that I've seen before include "Protective coat painters put on" , "Boilersuit" , "It protects a worker" , "Protective clothing" , "blanket" .)