easterner (n.)

"resident of an eastern land," in England, especially Hanse merchants and others from the North Sea Coast of Germany and the southern and eastern coast of the Baltic, early 15c., from easter, obsolete variant of eastern + -ling.

Old English easterne "of the east, from the east; oriental; of the Eastern Orthodox Church; of the eastern part of the globe," from east + -erne, suffix denoting direction. Cognate with Old Saxon ostroni, Old High German ostroni, Old Norse austroenn. Eastern Shore of Maryland and Virginia so called from 1620s.

English agent noun ending, corresponding to Latin -or. In native words it represents Old English -ere (Old Northumbrian also -are) "man who has to do with," from Proto-Germanic *-ari (cognates: German -er, Swedish -are, Danish -ere), from Proto-Germanic *-arjoz. Some believe this root is identical with, and perhaps a borrowing of, Latin -arius (see -ary).

Generally used with native Germanic words. In words of Latin origin, verbs derived from past participle stems of Latin ones (including most verbs in -ate) usually take the Latin ending -or, as do Latin verbs that passed through French (such as governor); but there are many exceptions (eraser, laborer, promoter, deserter; sailor, bachelor), some of which were conformed from Latin to English in late Middle English.

The use of -or and -ee in legal language (such as lessor/lessee) to distinguish actors and recipients of action has given the -or ending a tinge of professionalism, and this makes it useful in doubling words that have a professional and a non-professional sense (such as advisor/adviser, conductor/conducter, incubator/incubater, elevator/elevater).