Wiktionary
n. 1 Any true bug from the subfamily Reduviinae of the family Reduviidae, all of which eat other insects. They can inflict a very painful bite, but don't cause disease. 2 Any true bug from any of the subfamilies of the Reduviidae, including those in the subfamily Triatominae, which suck blood and may transmit Chagas' disease to humans.
WordNet
n. a true bug: long-legged predacious bug living mostly on other insects; a few suck blood of mammals [syn: reduviid]
Wikipedia
In the Dungeons & Dragons fantasy role-playing game, the assassin bug is a type of vermin creature.
Usage examples of "assassin bug".
Another insect, the assassin bug (sometimes called the masked bedbug hunter) was also welcomed in homes for years as a bedbug annihilator, until it was discovered that it bit people when it ran out of bedbugs.
The sight of the assassin bug downstairs earlier in the day had set her up for it, made her exaggerate the threat, for where there was one such bug there could be others, and they usually struck at night.
The sailor didn't have a weapon, but his long arms were spread like the claws of an assassin bug.