The Collaborative International Dictionary
Lambkill \Lamb"kill`\, n. (Bot.) A small American ericaceous shrub ( Kalmia angustifolia), resembling mountain laurel but having narrower leaves and small red flowers; -- called also calfkill, sheepkill, sheep laurel, etc. It is supposed to poison young sheep and other animals that eat it at times when the snow is deep and they cannot find other food.
Syn: sheep laurel, pig laurel, Kalmia angustifolia.