grille vs radiator grille

grille and radiator grille both are nouns.

Word	Noun	Adjective	Verb	Adverb
grille	Yes	No	No	No
radiator grille	Yes	No	No	No

As nouns, grille and radiator grille are synonyms defined as:

grille and radiator grille: grating that admits cooling air to car's radiator

grille (noun)	radiator grille (noun)
a framework of metal bars used as a partition or a grate	grating that admits cooling air to car's radiator
grating that admits cooling air to car's radiator
small opening (like a window in a door) through which business can be transacted