Plain English Meaning
Jet A is the standard kerosene fuel that turbine-powered aircraft burn. It is the fuel you put in jets and turboprops, and it is different from the gasoline used in piston aircraft.
Full Definition
Jet A is a kerosene-based turbine engine fuel used primarily in civil aviation in the United States. It has a flash point of approximately 100 °F and a freezing point of −40 °C, and is intended for use in turbine (jet and turboprop) engines, not piston engines.
Context Anchor
Seen in fuel grade discussions, aircraft , fuel truck , fueling , and checks around the fuel caps.