| Noun | 1. | armyworm - noctuid moth larvae that travel in multitudes destroying especially grass and graincaterpillar - a wormlike and often brightly colored and hairy or spiny larva of a butterfly or moth | |
| 2. | armyworm - moth whose destructive larvae travel in multitudesnoctuid, noctuid moth, owlet moth - usually dull-colored medium-sized nocturnal moth; the usually smooth-bodied larvae are destructive agricultural pests | |
| 3. | armyworm - larva of fungus gnat; march in large companies in regular order | |