A noun suffix denoting an agent or doer; as in auditor, one who hears; donor, one who gives; obligor, elevator. It is correlative to -ee. In general -or is appended to words of Latin, and -er to those of English, origin. See -er.
-OR
Meaning of -OR in English
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012