reboot (third-person singular simple present reboots, present participle rebooting, simple past and past participle rebooted) (computing, ergative) To execute a computer's boot process, effectively resetting the computer and causing the operating system to reload, commonly after a system failure. quotations if you reboot a computer, or if a computer reboots, you switch it off and then switch it on again a short time later, especially in order to get rid of a problem or after you have put new software onto the computer: Define reboot. reboot synonyms, reboot pronunciation, reboot translation, English dictionary definition of reboot. tr.v. re·boot·ed , re·boot·ing , re·boots 1. To turn off and then on again; restart. 2. To bring back , usually with a new cast and updated script. n. 4 meanings: 1. to shut down and restart (a computer system) or (of a computer system) to shut down and restart 2. informal to.... Click for more definitions.