King James Bible Dictionary

Heb. tsir'ah, "stinging", (Exodus 23:28; Deuteronomy 7:20; Joshua 24:12). The word is used in these passages as referring to some means by which the Canaanites were to be driven out from before the Israelites. Some have supposed that the word is used in a metaphorical sense as the symbol of some panic which would seize the people as a "terror of God" (Genesis 35:5), the consternation with which God would inspire the Canaanites. In Palestine there are four species of hornets, differing from our hornets, being larger in size, and they are very abundant. They "attack human beings in a very furious manner." "The furious attack of a swarm of hornets drives cattle and horses to madness, and has even caused the death of the animals."

Or wasp.
Exodus 23:28; Deuteronomy 7:20; Joshua 24:12

The hornet bears a general resemblance to the common wasp, only it is larger. It is exceedingly fierce and voracious, especially in hot climates and its sting is frequently dangerous. In Scripture the hornet is referred to only by the means which Jehovah employed for the extirpation of the Canaanites. (Exodus 23:28; 7:20; Joshua 24:12) Wisd. 12.8. (It is said that the Phaselit', a Phoenician people, were driven from their locality by hornets; and other examples are given in Paxton's "Illustrations of Scripture," 1.303. --ED.)

HORN'ET, noun An insect of the genus Vespa or wasp, the Vespa crabro. It is much larger and stronger than the wasp, and its sting gives severe pain. This insect constructs a nest of leaves or other substance which resembles brown paper of a light color. This is attached to the branches of trees, and often of the size of a half-peck measure.