1.NounA playthrough of a computer or video game in which the whole game or a select part of it, such as a single level, is played with the intent of completing it as quickly as possible, optionally with certain prerequisites.
"In the speedrun of Super Mario Bros. 3, Anonymous Jones finishes the whole game in just 11 minutes."
2.VerbTo perform or create a speedrun.
"In my most recent attempt to speedrun this game, I almost managed to beat the world record."
3.VerbTo do something or undergo some process as quickly as possible.
"John decided to speedrun his trip to the grocery store."