Definition of ignition in US English:



  • 1The action of setting something on fire or starting to burn.

    ‘three minutes after ignition, the flames were still growing’
    • ‘She activated something in her high heels and with a sudden ignition of fire from her actual heels, gently floated to the lonely and flooded street.’
    • ‘Sometimes, if the device fails to ignite first time, the tendency is to go back to check the fuse and then delayed ignition occurs which can cause injury to any part of the body.’
    • ‘Our descent into hell was caused by a bolt of lightening striking, with unerring accuracy, a vessel which contained a chemical that doesn't get on well with sources of ignition.’
    • ‘The cast-iron grate can hold 18 burgers, and one-touch ignition makes lighting the fire a cinch.’
    • ‘She questioned the health and safety representative, also on the possibility of ignition by a spark from a chimney fire, and of the likelihood of peat being ignited.’
    • ‘Keep away from sources of ignition and direct sunlight.’
    • ‘He said the fire was most likely to have been started by direct ignition to furniture in the room by an open flame like a match, cigarette lighter or candle.’
    • ‘Made of vitreous enamel, it boasts electronic multi-spark ignition in each of six burners, deluxe cast iron plates and a dual glass window roasting hood.’
    • ‘Eliminate ignition sources like open flames, smoking, static, electrical sparks and hot surfaces.’
    • ‘The ESU is the most frequent ignition source for surgical fires.’
    • ‘Fires were simple, so beautifully destructive, and yet so easy to get away with due to the lag time between ignition and full-blown flames.’
    • ‘At this stage we are treating it as suspected deliberate ignition.’
    • ‘While rumours are rife that a dropped cigarette or a spark from an underground cable caused the fireball, the cause of ignition was not yet known.’
    • ‘Any combustible material burns more rapidly when heated before ignition.’
    • ‘The danger is that the child s hand is still in the line of fire when ignition occurs and severe burns result.’
    • ‘Station officer Ian Hanley said they were treating the cause as deliberate ignition by youths.’
    • ‘Trail bikes, cars and any machinery are a potential source of ignition so please ensure that mufflers are secure and flame proofed to avoid sparks igniting the countryside.’
    • ‘The majority of cooking equipment fires start with the ignition of cooking oil from overheating.’
    • ‘Normally the risk of ignition is low, but fires may result if the temperature of the wires is initially set too high or if the wires are short-circuited in use.’
    burning, firing, kindling, igniting
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    1. 1.1 The process of starting the combustion of fuel in the cylinders of an internal combustion engine.
      • ‘The octane rating of a fuel is a measure its ability of to resist ignition under pressure.’
      • ‘In the early 70's came electronic ignition and electronic fuel injection.’
      • ‘Early ignition or runaway pre-ignition causes higher combustion chamber temperatures that can wreck the engine.’
      • ‘Combustion cycle doesn't stop at the compression stage wherein the air and fuel mixture is prepared for ignition.’
      • ‘This design of the flash reducer precludes ignition of the rocket motor for RAP.’
      • ‘A fourth strategy is to use water injection to slow the temperature rise in the combustion chamber, thereby delaying ignition until the charge is well mixed.’
      • ‘The SP Howitzer shall have a laser ignition system that shall provide for a minimum of 30 ignitions without replenishment of the ignition source.’
      • ‘At that speed, ignition and combustion take place in a matter of milliseconds.’
      • ‘The concept is creating a mixture of fuel and air capable of spontaneous ignition at multiple points instead of at a single location.’
      • ‘The newer fast ignition technique involves a two-part process of compression followed by ignition with a fast-heating pulse.’
      • ‘Other unusual engine features include valve timing control and direct fuel ignition.’
      explosion, discharge, blowing up, blast, burst, crack, bang, report
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    2. 1.2usually the ignition The mechanism for bringing about ignition in an internal combustion engine, typically activated by a key or switch.
      ‘he put the key in the ignition’
      • ‘Alice quickly followed her, closed the door, fumbled with the key before finally getting it into the ignition, switched in on, then took a few deep breaths.’
      • ‘Mr Wright told the court the group found the Maestro abandoned on some waste land near Wortley school with its ignition already damaged from being ‘hot wired’.’
      • ‘Before the key goes into the ignition, before the gear goes into drive, make sure you weigh all the risks.’
      • ‘Dodd makes two more trips to the Oldsmobile, first to turn off the car's ignition, then to unsuccessfully pull Dawson's left hand from under his leg.’
      • ‘PC Broadhurst got out, went over to the car and took the keys from its ignition.’
      • ‘Pitching the protesting owner onto the dock, he switched the ignition on.’
      • ‘When the couple got up the next morning they found the scooter flung on their lawn, its ignition ripped out, its battery damaged, and the seat vandalised.’
      • ‘He switched off the ignition and looked closely at Sai.’
      • ‘She adjusted the seat and mirror, fired up the ignition, and fiddled with the gear stick.’
      • ‘Thieves have been preying on motorists who leave their keys in the ignition and engines running to defrost their cars.’
      • ‘He claimed he couldn't switch off the ignition because modern Renaults have a magnetic card ‘key’ system and he was unable to remove the card while on the run.’
      • ‘I took the keys from the ignition of the jeep, and moved around back to the trunk.’
      • ‘Cat switched off the ignition and hopped out of the truck.’
      • ‘Buffy switched off the ignition and leaned forward, resting her forehead on the steering wheel.’
      • ‘He switched off the ignition and jumped from the car in one fluid motion.’
      • ‘After switching off the ignition, she climbed out.’
      • ‘He released the steering lock and switched on the ignition.’
      • ‘The victim took his keys from his car ignition and, after a short struggle, ran away with his keys in his hand.’
      • ‘With an auxiliary generator capability, the truck's generator can operate when the truck is parked without a key in the ignition.’
      • ‘He switched off the ignition and as he was about to take off his seatbelt a gunman appeared.’


Early 17th century (denoting the heating of a substance to the point of combustion or chemical change): from medieval Latin ignitio(n-), from the verb ignire ‘set on fire’ (see ignite).