noun

• (informal or archaic) The lungs.
  "“Why, who should J. B. mean by Joe, but old Joe Bagstock—Joseph—your slave—Joe, Ma’am? Here! Here’s the man! Here are the Bagstock bellows, Ma’am!” cried the Major, striking himself a sounding blow on the chest."
• (photography) Flexible, light-tight enclosures connecting the lensboard and the camera back.
• (figurative) That which fans the fire of hatred, jealousy, etc.

verb

• (intransitive, transitive) To operate a bellows; to direct air at (something) using a bellows.
  "[…] I was recommended to the place as a man who could give another man as good as he brought, and I took it. It’s easier than bellowsing and hammering."
• (intransitive, figuratively) To expand and contract like a bellows.
  "[…] [the dogs] sprang up, and, with a grand spraying of the crisp snow as they fleetly clambered up the steep side, they were with us in an incredibly short time, with pink tongues protruding, sides bellowsing, and sterns wagging."
• (transitive) To fold up like a bellows; to accordion.
  "Without being tight […] the boot leg should fit close. The ankle should be supple as a stocking, and “bellowsed” to make sure of suppleness."