The Collaborative International Dictionary
Amperometer
Ampere minute \Amp[`e]re minute\ and Ampere second \Amp[`e]re second\ are sometimes similarly used. [Webster 1913 Suppl.] ||Amperemeter \Am`p[`e]re"me`ter\, Amperometer \Am`pe*rom"e*ter\, n. [Amp[`e]re + meter.] (Physics) An instrument for measuring the strength of an electrical current in amp[`e]res.
Wiktionary
amperometer
n. (context rare English) An ammeter.