- either of the two saclike respiratory organs in the thorax of humans and the higher vertebrates.
- an analogous organ in certain invertebrates, as arachnids or terrestrial gastropods.
- as loudly as possible; with full voice: The baby cried at the top of his lungs.
- either one of a pair of spongy saclike respiratory organs within the thorax of higher vertebrates, which oxygenate the blood and remove its carbon dioxide
- any similar or analogous organ in other vertebrates or in invertebrates
- in one's loudest voice; yelling
