-or \-or\ [L. -or: cf. OF. -or, -ur, -our, F. -eur.]
1. A noun suffix denoting an act; a state or quality; as in
error, fervor, pallor, candor, etc.
2. 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}.