Protective garment, more than a couple of pounds (7)
I believe the answer is:
overall
'protective garment' is the definition.
(overall is a kind of protective garment)
'more than a couple of pounds' is the wordplay.
'more than' becomes 'over' (eg over 100 is more than 100).
'couple of' says to double the letters.
'pounds' becomes 'L' (L can represent the monetary pound).
'l' doubled is 'll'.
'over'+'a'+'ll'='OVERALL'
(Other definitions for overall that I've seen before include "It protects a worker" , "All round" , "Protective outer garment" , "Protective clothing" , "On the whole - protective garment" .)