Definition
A device in the induction system of a reciprocating engine that restricts airflow into the carburetor to produce a richer fuel-air mixture for starting a cold engine. By reducing the air entering the carburetor, the relative proportion of fuel increases, helping the engine fire when cold fuel does not vaporize easily.
Plain English
A part that temporarily limits the amount of air going into the engine so that more fuel reaches the cylinders, making it easier to start when the engine is cold.
Context Anchor
Seen in discussions of carbureted piston engines, engine starting procedures, and some cockpit engine controls.
Derivation
From Old English 'ceoke,' meaning to block or constrict the throat. The carburetor 'choke' literally narrows the air passage, restricting the engine's intake the same way a choked throat restricts breathing.
Why Pilots Care
Proper use prevents hard starts, flooding, or damage to the engine in cold conditions.
Intuition Check
Do not read choke here as simply “to stop” or “to suffocate.” In this context, it means to reduce airflow into the carburetor so the engine gets a richer starting mixture.
Example Sentence 1
On a cold morning, the pilot pulled the choke out before starting the engine, then pushed it back in once the engine warmed up.
Example Sentence 2
Once the engine was running smoothly, he pushed the choke knob back in.