to register, as for a school or college, before the main registration period
verbpre·reg·is·tered, pre·reg·is·ter·ing, pre·reg·is·ters
To take part in preregistration.
To enroll (a student) during a period of preregistration.
(third-person singular simple present preregisters, present participle preregistering, simple past and past participle preregistered)