big bedbug vs reduviid

big bedbug and reduviid both are nouns.

Word	Noun	Adjective	Verb	Adverb
big bedbug	Yes	No	No	No
reduviid	Yes	No	No	No

As nouns, reduviid is a hypernym of big bedbug; that is, reduviid is a word with a broader meaning than big bedbug:

big bedbug: large bloodsucking bug
reduviid: a true bug: long-legged predacious bug living mostly on other insects; a few suck blood of mammals

Other hypernyms of big bedbug include assassin bug.

big bedbug (noun)	reduviid (noun)
large bloodsucking bug	a true bug: long-legged predacious bug living mostly on other insects; a few suck blood of mammals