gill

(noun) a British imperial capacity unit (liquid or dry) equal to 5 fluid ounces or 142.066 cubic centimeters.

(noun) a United States liquid unit equal to 4 fluid ounces.

(noun) any of the radiating leaflike spore-producing structures on the underside of the cap of a mushroom or similar fungus. Synonyms: lamella.

(noun) respiratory organ of aquatic animals that breathe oxygen dissolved in water. Synonyms: branchia.