The dram (alternative British spelling drachm; apothecary symbol ʒ or ℨ; abbreviated dr) Earlier version first published in ''

New English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first editi ...

'', 1897.National Institute of Standards and Technology (October 2011). Butcher, Tina; Cook, Steve; Crown, Linda et al. eds
"Appendix C – General Tables of Units of Measurement"
(PDF)
''Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices''
NIST Handbook. 44 (2012 ed.). Washington, D.C.: U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology.

ISSN An International Standard Serial Number (ISSN) is an eight-digit to uniquely identify a periodical publication (periodical), such as a magazine. The ISSN is especially helpful in distinguishing between serials with the same title. ISSNs a ...

br>0271-4027

OCLC OCLC, Inc. See also: is an American nonprofit cooperative organization "that provides shared technology services, original research, and community programs for its membership and the library community at large". It was founded in 1967 as the ...

. Retrieved 1 July 2012. is a unit of

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

in the

avoirdupois Avoirdupois (; abbreviated avdp.) is a measurement system of weights that uses pounds and ounces as units. It was first commonly used in the 13th century AD and was updated in 1959. In 1959, by international agreement, the definitions of the p ...

system, and both a unit of mass and a unit of volume in the

apothecaries' system The apothecaries' system, or apothecaries' weights and measures, is a historical system of mass and volume units that were used by physicians and apothecaries for medical prescriptions and also sometimes by scientists."Medicinal-Gewicht, Apotheke ...

. It was originally both a

coin A coin is a small object, usually round and flat, used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to facilitate trade. They are most often issued by ...

and a

weight In science and engineering, the weight of an object is a quantity associated with the gravitational force exerted on the object by other objects in its environment, although there is some variation and debate as to the exact definition. Some sta ...

ancient Greece Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically r ...

. The unit of volume is more correctly called a fluid dram, fluid drachm, fluidram or fluidrachm (abbreviated fl dr, ƒ 3, or fʒ).

Ancient unit of mass

*The Attic

Greek drachma Drachma may refer to: * Ancient drachma, an ancient Greek currency * Modern drachma, a modern Greek currency (1833...2002) * Cretan drachma, currency of the former Cretan State * Drachma proctocomys, moth species, the only species in the Genus ...

() was a weight of 6 obols, Greek mina, or about 4.37

gram The gram (originally gramme; SI unit symbol g) is a Physical unit, unit of mass in the International System of Units (SI) equal to one thousandth of a kilogram. Originally defined in 1795 as "the absolute Mass versus weight, weight of a volume ...

s. * The Roman drachma was a weight of Roman pounds, or about 3.41 grams. A coin weighing one drachma is known as a

stater The stater (; ) was an ancient coin used in various regions of Greece. The term is also used for similar coins, imitating Greek staters, minted elsewhere in ancient Europe. History The stater, as a Greek silver currency, first as ingots, and ...

, drachm, or drachma. The Ottoman

dirhem The dirham, dirhem or drahm is a unit of currency and of mass. It is the name of the currencies of Morocco, the United Arab Emirates and Armenia, and is the name of a currency subdivision in Jordan, Libya, Qatar and Tajikistan. It was historicall ...

() was based on the

Sassanian The Sasanian Empire (), officially Eranshahr ( , "Empire of the Iranian peoples, Iranians"), was an List of monarchs of Iran, Iranian empire that was founded and ruled by the House of Sasan from 224 to 651. Enduring for over four centuries, th ...

drachm, which was itself based on the Roman dram/drachm.

British unit of mass

The British

Weights and Measures Act 1878 Weights and Measures Acts are acts of the British Parliament determining the regulation of weights and measures. It also refers to similar royal and parliamentary acts of the Kingdoms of England and Scotland and the medieval Welsh states. ...

introduced verification and consequent stamping of apothecary weights, making them officially recognized units of measurement. By 1900, Britain had enforced the distinction between the avoirdupois and apothecaries' versions by making the spelling different: *''dram'' now meant only avoirdupois drams, which were of an avoirdupois ounce. An ounce consisted of 437.5

grain A grain is a small, hard, dry fruit (caryopsis) – with or without an attached husk, hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and ...

s, thus making the dram exactly 27.34375 grains. *''drachm'' now meant only apothecaries' drachms, which were of an apothecaries' ounce of 480 grains, or equal to 60 grains.

Modern unit of mass

In the

system, the dram is the mass of

pound Pound or Pounds may refer to: Units * Pound (currency), various units of currency * Pound sterling, the official currency of the United Kingdom * Pound (mass), a unit of mass * Pound (force), a unit of force * Rail pound, in rail profile * A bas ...

ounce The ounce () is any of several different units of mass, weight, or volume and is derived almost unchanged from the , an Ancient Roman unit of measurement. The avoirdupois ounce (exactly ) is avoirdupois pound; this is the United States ...

. The dram weighs

grains A grain is a small, hard, dry fruit ( caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and le ...

, or exactly grams. In the

, which was widely used in the United States until the middle of the 20th century, the dram is the mass of pounds apothecaries (lb ap), or ounces apothecaries (oz ap or ℥) (the pound apothecaries and ounce apothecaries are equal to the

troy pound Troy weight is a system of Physical unit, units of mass that originated in the Kingdom of England in the 15th century and is primarily used in the precious metals industry. The troy weight units are the Grain (unit), grain, the pennyweight (24 ...

(lb t), and

troy ounce Troy weight is a system of units of mass that originated in the Kingdom of England in the 15th century and is primarily used in the precious metals industry. The troy weight units are the grain, the pennyweight (24 grains), the troy ounce (20 p ...

(oz t), respectively). The dram apothecaries is equal to or , or exactly grams. "Dram" is also used as a measure of the powder charge in a shotgun shell, representing the equivalent of black powder in drams avoirdupois.

Unit of volume

The ''fluid dram'' (or ''fluid drachm'' in British spelling) is defined as

fluid ounce 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. The British Imperial, the United States customary, and the United S ...

, and is equal to: * in the U.S. customary system * in the British imperial system