Home › Words › O › ostiariusostiariusostiarius means an ostiary; a doorman; a porter.EtymologyBorrowed from Latin ōstiārius.nounAn ostiary; a doorman; a porter.A student office held by a prefect with the duties of keeping order, collecting the vulguses, and ensuring the other students attend class.Definitions & examples from Wiktionary (CC BY-SA 3.0).