Godan verb with 'su' ending, Intransitive verb
to run out; to rush out
そうだな、私の時計が止まったので彼が時間を知っているかどうか、たずねただけだ。彼はただ駆け出しただけだ。Well, I just asked him if he knew the time, because my watch has stopped, and he simply bolted. to start running; to begin to run; to break into a run
Also written 駈け出す【かけだす】