In aviation terminology, a rejected takeoff (RTO) or aborted takeoff is the situation in which it is decided to abort the takeoff of an airplane. There can be many reasons for deciding to perform a rejected takeoff, but they are usually due to suspected or actual technical failures, like an engine failure such as a compressor stall occurring during the takeoff run.
A rejected takeoff is normally performed only if the aircraft's speed is below the takeoff decision speed known as V1, which for larger multi-engined airplanes is calculated before each flight. Below the decision speed the airplane should be able to stop safely before the end of the runway. Above the decision speed, the airplane may overshoot the runway if the takeoff is aborted and therefore a rejected takeoff is normally not performed above this speed, unless there is reason to doubt the airplane's ability to fly. If a serious failure occurs or is suspected above V1 but the airplane's ability to fly is not in doubt, the takeoff is continued despite the (suspected) failure and the airplane will attempt to land again as soon as possible.