ignition

noun

ig·​ni·​tion ig-ˈni-shən 

1

a

: the device that is used to ignite the fuel mixture in a gasoline engine

put the key in the ignition

b

: the process or means (such as an electric spark) of igniting a fuel mixture

2

: the act or action of igniting: such as

a

: the starting of a fire

b

: the heating of a plasma to a temperature high enough to sustain nuclear fusion

Examples of ignition in a Sentence

There's a problem with the car's ignition.

Recent Examples on the Web

The keys were in the ignition and the doors were unlocked. —Jason Green, Mercury News, 3 Aug. 2025

The new law focuses on reforming the use of ignition interlock — a Breathalyzer device installed in a car for DWI offenders that checks if a driver has been drinking alcohol before the car can start. —Mary Murphy, Twin Cities, 30 July 2025

Since then, she’s overseen the first lab demonstration of a fusion ignition and the lab’s installation of the world’s fastest supercomputer, El Capitan, a $600 million project that began in 2023. —Maggie McGrath, Forbes.com, 30 July 2025

The latest results come after the successful fusion ignition in 2022 at the National Ignition Facility (NIF) near San Francisco, which used a very different method of fusion called inertial confinement. —Tom Metcalfe, Scientific American, 2 July 2025

Word History

First Known Use

1612, in the meaning defined at sense 2

Rhymes for ignition

• addition
• admission
• ambition
• attrition
• audition
• clinician
• cognition
• coition
• commission
• condition
• contrition
• dentition

Kids Definition

ignition

noun

ig·​ni·​tion ig-ˈnish-ən 

1

: the act of igniting

2

: the process or means (as an electric spark) of igniting a fuel mixture

also : an electrical device for operating an ignition system (as in an automobile)

put the key in the ignition