gram (n.)

also gramme, metric unit of weight, 1797, from French gramme (18c.), from Late Latin gramma "small weight," from Greek gramma "small weight," a special use of the classical word meaning "a letter of the alphabet" (see -gram). Adopted into English about two years before it was established in France as a unit in the metric system by law of 19 frimaire, year VIII (1799). "There seems to be no possible objection to adopting the more convenient shorter form, except that the -me records the unimportant fact that the word came to us through French" [Fowler].

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Definitions of gram from WordNet
gram (n.)
a metric unit of weight equal to one thousandth of a kilogram;
Synonyms: gramme / gm / g
Gram (n.)
Danish physician and bacteriologist who developed a method of staining bacteria to distinguish among them (1853-1938);
Synonyms: Hans C. J. Gram