Protective garment a professional nurse first needed (5)
I believe the answer is:
apron
'protective garment' is the definition.
(apron is a kind of protective garment)
'a professional nurse first needed' is the wordplay.
'professional' becomes 'pro' (abbreviation).
'nurse first' becomes 'n' (1st letter of 'nurse').
'needed' means one lot of letters go next to another.
'a'+'pro'+'n'='APRON'
(Other definitions for apron that I've seen before include "Garment for protection" , "Kitchen garment or part of airfield" , "Protective garment - part of stage" , "Protective garment worn at front" , "Area for aircraft not in use" .)