Nitpicking continued: As per e.g. Wikipedia definition it refers explicitly to the process (and not the speed): "In civil and military jurisprudence, summary execution is the putting to death of a person accused of a crime without the benefit of a free and fair trial. The term results from the legal concept of summary justice to punish a summary offense, as in the case of a drumhead court-martial, but the term usually denotes the summary execution of a sentence of death."

In practice a free and fair trial can't be very fast though.

https://en.m.wikipedia.org/wiki/Summary_execution