birth control device vs preventive

birth control device and preventive both are nouns.

Word	Noun	Adjective	Verb	Adverb
birth control device	Yes	No	No	No
preventive	Yes	Yes	No	No

As nouns, birth control device and preventive are synonyms defined as:

birth control device and preventive: an agent or device intended to prevent conception

Other synonyms of birth control device include contraceptive, contraceptive device, preventative, prophylactic device.

birth control device (noun)	preventive (noun)
an agent or device intended to prevent conception	remedy that prevents or slows the course of an illness or disease
	an agent or device intended to prevent conception
	any obstruction that impedes or is burdensome

birth control device (adjective)	preventive (adjective)
	tending to prevent or hinder
	preventing or contributing to the prevention of disease