- -or [ər, ôr]suffix1. [ME -our < OFr -our, -or, -eur < L -or, -ator] a person or thing that (does a specified thing) [mortgagor, incisor]2. [ME -our < OFr < L -or] quality or condition [favor, error]USAGE- for several words with this suffix, e.g. ardor, armor, color, endeavor, favor, honor, labor, rumor, savior, the spelling suffix -our is standard usage or a common alternate spelling in most other English-speaking countries ( ardour, armour, colour, etc.); other words, e.g. error, liquor, pallor, terror, are now always spelled with -OR
English World dictionary. V. Neufeldt. 2014.