Source : Webster's Revised Unabridged Dictionary (1913)

Lungworm \Lung"worm`\, n. (Zo["o]l.)
   Any one of several species of parasitic nematoid worms which
   infest the lungs and air passages of cattle, sheep, and other
   animals, often proving fatal. The lungworm of cattle
   ({Strongylus micrurus}) and that of sheep ({S. filaria}) are
   the best known.