gill (Noun) — A British imperial capacity unit (liquid or dry) equal to 5 fluid ounces or 142.066 cubic centimetres.
gill (Noun) — A United States liquid unit equal to 4 fluid ounces.
gill (Noun) — Any of the radiating leaflike spore-producing structures on the underside of the cap of a mushroom or similar fungus.
gill (Noun) — Respiratory organ of aquatic animals that breathe oxygen dissolved in water.
gill (Noun) — A ravine or stream.