any of a family (Reduviidae) of large brownish hemipteran insects that kill other insects and suck the life fluids from them: some species suck blood from mammals and may transmit Chagas' disease to humans
See assassin bug in American Heritage Dictionary 4
noun
Any of various predatory bugs of the family Reduviidae, which have short, curved, powerful beaks used to prey on other insects or, in certain genera, modified to suck blood from mammals. Also called reduviid.