any of various mainly tropical American predatory ants of the subfamily Dorylinae, which live in temporary nests and travel in vast hordes preying on other animals
Also called: legionary ant. See also driver ant
army ant in American English
any of a number of carnivorous ants that travel in long lines and prey on insects and animals in their path; esp., any of a genus (Eciton) of such ants of the American tropics and S U.S.