What is "fluid ounce"

Fluid \Flu"id\, n. A fluid substance; a body whose particles move easily among themselves. Note: Fluid is a generic term, including liquids and gases as species. Water, air, and steam are fluids. By analogy, the term was sometimes applied to electricity and magnetism, as in phrases electric fluid, magnetic fluid, though not strictly appropriate; such usage has disappeared. Fluid dram, or Fluid drachm, a measure of capacity equal to one eighth of a fluid ounce. Fluid ounce.

1. In the United States, a measure of capacity, in apothecaries' or wine measure, equal to one sixteenth of a pint or 29.57 cubic centimeters. This, for water, is about 1.04158 ounces avoirdupois, or 455.6 grains.

2. In England, a measure of capacity equal to the twentieth part of an imperial pint. For water, this is the weight of the avoirdupois ounce, or 437.5 grains.

   Fluids of the body. (Physiol.) The circulating blood and lymph, the chyle, the gastric, pancreatic, and intestinal juices, the saliva, bile, urine, aqueous humor, and muscle serum are the more important fluids of the body. The tissues themselves contain a large amount of combined water, so much, that an entire human body dried in vacuo with a very moderate degree of heat gives about 66 per cent of water.

   Burning fluid, Elastic fluid, Electric fluid, Magnetic fluid, etc. See under Burning, Elastic, etc.

Ounce \Ounce\ (ouns), n. [F. once, fr. L. uncia a twelfth, the twelfth part of a pound or of a foot: cf. Gr. 'o`gkos bulk, mass, atom. Cf. 2d Inch, Oke.]

1. A weight, the sixteenth part of a pound avoirdupois, and containing 28.35 grams or 4371/2 grains.

2. (Troy Weight) The twelfth part of a troy pound; one troy ounce weighs 31.103486 grams, 8 drams, or 480 grains.

   Note: The troy ounce contains twenty pennyweights, each of twenty-four grains, or, in all, 480 grains, and is the twelfth part of the troy pound. The troy ounce is also a weight in apothecaries' weight. [Troy ounce is sometimes written as one word, troyounce.]

3. Fig.: A small portion; a bit. [Obs.]

   By ounces hung his locks that he had.
   --Chaucer.

   Fluid ounce. See under Fluid, n.

n. Any of various units of volume used for liquid measure, all approximately 1.73–1.83 cubic inches or 28.4–30 milliliters.

1. n. a British imperial unit of capacity or volume (liquid or dry) equal to 8 fluid drams or 28.416 cubic centimeters (1.734 cubic inches) [syn: fluidounce]

2. a United States unit of capacity or volume equal to 1.804 cubic inches [syn: fluidounce]

A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl., old forms ℥, fl ℥, f℥, ƒ ℥) is a unit of volume (also called capacity) typically used for measuring liquids. It is equivalent to approximately 30 millilitres. Whilst various definitions have been used throughout history, two remain in common use: the imperial and the United States customary fluid ounce. An imperial fluid ounce is of an imperial pint, of an imperial gallon or approximately 28.4 ml. A US fluid ounce is of a US fluid pint, of a US liquid gallon or approximately 29.6 ml. The fluid ounce is distinct from the ounce, a unit of weight or mass, although they do have a historical relationship, and it is sometimes referred to simply as an "ounce" where context makes the meaning clear.