gill vs plastron

gill

noun
  • A gill slit or gill cover. 

  • One of the combs of closely ranged steel pins which divide the ribbons of flax fiber or wool into fewer parallel filaments. 

  • The fleshy flap that hangs below the beak of a fowl; a wattle. 

  • One of the radial folds on the underside of the cap of a mushroom, the surface of which bears the spore-producing organs. 

  • A breathing organ of fish and other aquatic animals. 

  • ravine 

  • a two-wheeled frame for transporting timber 

  • rivulet 

  • a female ferret 

  • The flesh under or about the chin; a wattle. 

  • A drink measure for spirits and wine, approximately a quarter of a pint, but varying regionally. 

verb
  • To be or become entangled in a gillnet. 

  • To catch (a fish) in a gillnet. 

  • To remove the gills from a fish as part of gutting and cleaning it. 

plastron

noun
  • A film of air trapped by specialized hairs against the body of an aquatic insect, and which acts as an external gill. 

  • A breastplate. 

  • A half-jacket worn under the jacket for padding or for safety. 

  • The nearly flat part of the shell structure of a tortoise or other animal, similar in composition to the carapace. 

  • An ornamental front panel on a woman's bodice. 

  • A man's shirt-bosom. 

How often have the words gill and plastron occurred in a corpus of books? (source: Google Ngram Viewer )