In favour of wearing article, a protective garment (5)
I believe the answer is:
apron
'a protective garment' is the definition.
(apron is a kind of protective garment)
'in favour of wearing article' is the wordplay.
'in favour of' becomes 'pro' (I've seen this before).
'wearing' is an insertion indicator.
'article' becomes 'an' (indefinite article).
'pro' going within 'an' is 'APRON'.
(Other definitions for apron that I've seen before include "Protective garment - type of stage" , "Space in front of curtain" , "Part of stage in front of the curtain" , "Domestic protection" , "Protective garment worn at front" .)