Pronunciation: (lung), [key]
1. either of the two saclike respiratory organs in the thorax of humans and the higher vertebrates.
2. an analogous organ in certain invertebrates, as arachnids or terrestrial gastropods.
3. at the top of one's lungs, as loudly as possible; with full voice: The baby cried at the top of his lungs.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.