Definition from Nolo’s Plain-English Law Dictionary

A rule that allows a killing that occurs in the course of a dangerous felony, even an accidental death, to be charged against the felon as first-degree murder. A felon can be guilty of murder during the course of the dangerous felony even if the felon is not the killer, as might happen when a robber kills a clerk -- the driver of the getaway car, as well as the robber, may be charged with first-degree murder. The rule extends to unusual circumstances, such as the killing of one of two bank robbers by a bank security officer (the surviving robber may be charged with murder).

Definition provided by Nolo’s Plain-English Law Dictionary.