- any nematode worm of the superfamily Metastrongylidae, parasitic in the lungs of various mammals.
- a nematode worm of the genus Rhabdias, parasitic in the lungs of reptiles and amphibians.
- any parasitic nematode worm of the family Metastrongylidae, occurring in the lungs of mammals, esp Metastrongylus apri which infects pigs
- any of certain other nematodes that are parasitic in the lungs
