ounce

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A unit of weight in the U.S. Customary System, an avoirdupois unit equal to 437.5 grains (28.35 grams).
2. n. A unit of apothecary weight, equal to 480 grains (31.10 grams). See Table at measurement.
3. n. A fluid ounce. See Table at measurement.
4. n. A tiny bit: not an ounce of sympathy.
5. n. See snow leopard.

Century Dictionary and Cyclopedia

1. n. A weight, the twelfth part of a pound troy, and the sixteenth of a pound avoirdupois. In troy weight the ounce is 20 pennyweights, each of 24 grains, the ounce being therefore 480 grains; in avoirdupois weight the ounce is equal to 437½ grains. The ounce was originally the Roman duodecimal subdivision of the pound. In modern systems it is generally a twelfth or sixteenth of a pound. Abbreviated oz.
2. n. A small quantity.
3. n. In California, in the earlier years of the gold excitement, a Spanish double doubloon, or about sixteen dollars; the old doubloon onza of Spain.
4. n. A carnivorous mammal, Felis irbis or F. uncia, of the cat family, Felidæ, closely related to but distinct from the other large spotted cats known as leopards or panthers; the snow-leopard or mountain panther. It is an alpine animal, inhabiting the mountains of Asia up to an altitude of 18,000 feet, and bearing the same relation to the leopards of warmer regions that the Canada lynx, for example, bears to the ordinary bay lynx or wildcat. In consequence of its habitat the fur is very-thick and long, even forming a mane on the back, and the color is pale-gray with obsolete dark spotting, instead of reddish with sharp black spotting as in the leopards of low countries. The muzzle is notably obtuse, with arched frontal profile, in consequence of the shortness of the nasal bones.
5. n. The bay lynx or the Canada lynx.
6. n. An occasional name of the American jaguar, Felis onca.
7. n. A gold coin of Australia struck in 1853.

Wiktionary

1. n. The snow leopard, Uncia uncia.
2. n. An avoirdupois ounce, weighing 1/16 of an avoirdupois pound, or 28.3495 grams.
3. n. A troy ounce, weighing 1/12 of a troy pound, or 480 grains, or 31.1035 grams.
4. n. A US fluid ounce, with a volume of 1/16 of a US pint, 1.804 687 cubic inches or 29.573 531 milliliters.
5. n. A British imperial fluid ounce, with a volume of 1/20 of an imperial pint, 1.733871 cubic inches or 28.413063 milliliters.
6. n. A little bit.

GNU Webster's 1913

1. n. A weight, the sixteenth part of a pound avoirdupois, and containing 28.35 grams or 4371/2 grains.
2. n. (Troy Weight) The twelfth part of a troy pound; one troy ounce weighs 31.103486 grams, 8 drams, or 480 grains.
3. n. obsolete Fig.: A small portion; a bit.
4. n. (Zoöl.) A feline quadruped (Felis irbis syn. Felis uncia) resembling the leopard in size, and somewhat in color, but it has longer and thicker fur, which forms a short mane on the back. The ounce is pale yellowish gray, with irregular dark spots on the neck and limbs, and dark rings on the body. It inhabits the lofty mountain ranges of Asia. Called also once.

WordNet 3.0

1. n. a unit of weight equal to one sixteenth of a pound or 16 drams or 28.349 grams
2. n. large feline of upland central Asia having long thick whitish fur
3. n. a unit of apothecary weight equal to 480 grains or one twelfth of a pound