primer vs couch

primer and couch both are nouns.

Word	Noun	Adjective	Verb	Adverb
primer	Yes	No	No	No
couch	Yes	No	Yes	No

As nouns, couch is a hyponym of primer; that is, couch is a word with a more specific, narrower meaning than primer:

primer (noun)	couch (noun)
any igniter that is used to initiate the burning of a propellant	an upholstered seat for more than one person
the first or preliminary coat of paint or size applied to a surface	a narrow bed on which a patient lies during psychiatric or psychoanalytic treatment
an introductory textbook	a flat coat of paint or varnish used by artists as a primer

primer (verb)	couch (verb)
	formulate in a particular style or language