ampere

noun

am·​pere ˈam-ˌpir 

also

-ˌper 

plural amperes

1

: the practical meter-kilogram-second unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm

2

: the base unit of electric current in the International System of Units that is defined by setting the fixed numerical value of the elementary charge to 1.602176634 x 10^-19 ampere seconds

Examples of ampere in a Sentence

a current of 15 amperes

Recent Examples on the Web

For example, a battery with 10,000 milliampere hour rating is equal to 10 ampere hours. — ABC News, 3 June 2026

The 100 kilovolt ampere (kVA) hydrogen generator powered the film’s entire unit basecamp and contributed to an overall reduction in diesel generator fuel usage by over 50%, according to Netflix. — Todd Spangler, Variety, 22 Apr. 2026

Rethinking anode design During testing, the prototype silicon-graphene anode retained over 98 percent of its capacity after more than 2,000 cycles at a current density of five amperes per gram (A g-1), with negligible decay compared to non-lithiated counterparts. — Georgina Jedikovska, Interesting Engineering, 18 Mar. 2026

The gear, which includes the suit, gloves, and socks, protects against 100 amperes for 10 seconds and 50 A for 30 seconds. — IEEE Spectrum, 12 Jan. 2026

Word History

Etymology

André-Marie Ampère

First Known Use

1881, in the meaning defined at sense 1

Phrases Containing ampere

• ampere-hour
• ampere-turn
• volt-ampere

Rhymes for ampere

• adhere
• ameer
• amir
• appear
• arrear
• astir
• austere
• career
• cashier
• cohere
• compere
• emir

Kids Definition

ampere

noun

am·​pere ˈam-ˌpi(ə)r 

: a unit for measuring the rate of flow of an electric current

Medical Definition

ampere

noun

am·​pere

ˈam-ˌpi(ə)r also -ˌpe(ə)r

1

: the practical mks unit of electric current that is equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm

2

: the base unit of electric current in the International System of Units that is equal to a constant current which when maintained in two straight parallel conductors of infinite length and negligible circular sections one meter apart in a vacuum produces between the conductors a force equal to 2 × 10⁻⁷ newton per meter of length

Biographical Definition

Ampère

biographical name

Am·​père äⁿ-ˈper 

André-Marie 1775–1836 French physicist