1881, "the current that one volt can send through one ohm," from French ampère, named for French physicist André-Marie Ampère (1775-1836). Shortened form amp is attested from 1886.
ampere am·pere (ām'pēr')
n.
Abbr. A
A unit of electric current in the meter-kilogram-second system, equal to the current that, flowing in two parallel wires one meter apart, produces a force of 2 × 10-7 newtons per meter.
A unit in the International System specified as one International coulomb per second and equal to 0.999835 ampere.
unit of electric current in the Systeme International d'Unites (SI), used by both scientists and technologists. Since 1948 the ampere has been defined as the constant current which, if maintained in two straight parallel conductors of infinite length of negligible circular cross section and placed one metre apart in a vacuum, would produce between these conductors a force equal to 2 10-7 newton per metre of length. Named for the 19th-century French physicist Andre-Marie Ampere, it represents a flow of one coulomb of electricity per second. A flow of one ampere is produced in a resistance of one ohm by a potential difference of one volt. See electric current.