register 1 adj. It applies to what registers or leaves something noted: Cash register . 2 n. Official in charge of a public registry. If not specified, it is understood as property registrar : Registrations have been announced to registrars . 3 m. Official who formerly carried the register of cedulas, offices, privileges, etc., given by the king, the councils or courts of the kingdom, etc. 4 n. Person in charge of registering the genres that enter or leave a population. Registrar of the property. Official of those in charge of property records. V. cash register .