primer vs flat coat

primer and flat coat both are nouns.

Word	Noun	Adjective	Verb	Adverb
primer	Yes	No	No	No
flat coat	Yes	No	No	No

As nouns, primer and flat coat are synonyms defined as:

primer and flat coat: the first or preliminary coat of paint or size applied to a surface

Other synonyms of primer include ground, primer coat, priming, priming coat, undercoat.

primer (noun)	flat coat (noun)
any igniter that is used to initiate the burning of a propellant	the first or preliminary coat of paint or size applied to a surface
the first or preliminary coat of paint or size applied to a surface
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