preventive vs obstructor

preventive and obstructor both are nouns.

Word	Noun	Adjective	Verb	Adverb
preventive	Yes	Yes	No	No
obstructor	Yes	No	No	No

As nouns, obstructor is a hypernym of preventive; that is, obstructor is a word with a broader meaning than preventive:

Other hypernyms of preventive include impediment, impedimenta, obstructer, obstruction.

preventive (noun)	obstructor (noun)
remedy that prevents or slows the course of an illness or disease	any structure that makes progress difficult
an agent or device intended to prevent conception	someone who systematically obstructs some action that others want to take
any obstruction that impedes or is burdensome

preventive (adjective)	obstructor (adjective)
tending to prevent or hinder
preventing or contributing to the prevention of disease