Lung

n.
  1. An organ for aërial respiration; -- commonly in the plural.
    2. Lung fever (Med.),
    pneumonia.
    Lung flower (Bot.),
    a species of gentian (Gentian Pneumonanthe).
    Lung lichen (Bot.),
    tree lungwort. See under Lungwort.
    Lung sac (Zoöl.),
    one of the breathing organs of spiders and snails.