Million with request for form of protection (4)
I believe the answer is:
mask
'form of protection' is the definition.
(I know that mask is a type of protection)
'million with request' is the wordplay.
'million' becomes 'm' (abbreviation).
'with' says to put letters next to each other.
'request' becomes 'ask' (to ask is to request something).
'm'+'ask'='MASK'
'for' acts as a link.
(Other definitions for mask that I've seen before include "cloak" , "Conceal" , "Face-covering" , "Visor; disguise" , "Face covering; disguise" .)