What is the meaning of Bedbug?

A small nocturnal insect pest of humans, of species Cimex lectularius (common bedbug) and Cimex hemipterus (tropical bedbug) that feeds on the blood of humans during sleep.

Any similar insect of family Cimicidae, that feeds on the blood of humans and certain other warm-blooded animals.

Source: wiktionary.org