impolite adj.

word-forming element meaning "not, opposite of, without" (also im-, il-, ir- by assimilation of -n- with following consonant, a tendency which began in later Latin), from Latin in- "not," cognate with Greek an-, Old English un-, all from PIE root *ne- "not."

In Old French and Middle English often en-, but most of these forms have not survived in Modern English, and the few that do (enemy, for instance) no longer are felt as negative. The rule of thumb in English has been to use in- with obviously Latin elements, un- with native or nativized ones.

late 14c., "polished, burnished" (mid-13c. as a surname), from Latin politus "refined, elegant, accomplished," literally "polished," past participle of polire "to polish, to make smooth" (see polish (v.)).

The literal sense is obsolete in English; the sense of "elegant, cultured" (of literature, arts, etc.) is from c. 1500; of persons, "refined or cultivated in speech, manner, or behavior," by 1620s. The meaning "behaving courteously, showing consideration for others" is by 1748 (implied in politely). Related: Politeness.

Polite applies to one who shows a polished civility, who has a higher training in ease and gracefulness of manners: politeness is a deeper, more comprehensive, more delicate, and perhaps more genuine thing than civility. Polite, though much abused, is becoming the standard word for the bearing of a refined and kind person toward others. [Century Dictionary, 1895]

1670s, from impolite + -ness.