An Etymological Dictionary of Astronomy and Astrophysics

A unit of mass equal to one thousandth of a kilogram.

Etymology (EN): From Fr. gramme, from L.L. gramma “small weight,” from Gk. gramma “small weight,” originally “letter of the alphabet,” from stem of graphein “to draw, write.”

Etymology (PE): Geram, loanword from Fr. gramme, as above.