1. Either of two spongy, saclike respiratory organs in air-breathing vertebrates, occupying the chest cavity together with the heart and functioning to provide oxygen to the blood while removing carbon dioxide.
2. A similar organ in some invertebrates, including spiders and terrestrial snails.
at the top of (one's) lungs
As loudly as one's voice will allow.
[Middle English lunge, from Old English lungen, lungs; see legwh- in the Appendix of Indo-European roots.]
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