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

Lightning creates a continuing current with durations ranging from tens to hundreds of milliseconds and exhibit amplitudes from several tens to a few hundreds of amperes. —Sabbir Rangwala, Forbes.com, 11 June 2025

The company claims its 1,000 ampere current and 10-C charging rate are global records for any EV battery. —IEEE Spectrum, 6 June 2025

Many Bissell vacuums have around 9 amperes of power, although some are as high as 12. —Bestreviews, Chicago Tribune, 18 Mar. 2025

One hundred amperes is equivalent to the electrical service provided to many households. —David Wallace, CBS News, 14 May 2024

For a large generator, this can amount to thousands of amperes. —Benjamin Kroposki, IEEE Spectrum, 13 Apr. 2024

The rate of flow is measured in amperes: 1 amp = 6.24 x 1018 electrons flowing through a certain point per second. —Rhett Allain, WIRED, 23 Feb. 2024

The unit of electric current known as the ampere, or amp for short, is named after the founder of electrodynamics. —IEEE Spectrum, 11 July 2023

The digital circuit breaker is also about 3,000 times as fast as most mechanical breakers, enabling circuit interruption capabilities up to 150,000 amperes, the upper limit for today’s circuit breakers. —IEEE Spectrum, 20 June 2023

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