four-stroke cycle

noun

: a cycle in which air or an explosive mixture is drawn into the cylinder of an internal-combustion engine on a suction stroke, is compressed and ignited on a compression stroke, burns and performs useful work on an expansion stroke, and expels the products of combustion on an exhaust or scavenging stroke

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!