Impolite, a.
Etymology: [L. impolitus unpolishied, pref. im- not + politus, p. p. of polire to polish, refine. See Polite.]
Not polite; not of polished manners; wanting in good manners; discourteous; uncivil; rude. -- Im`po*lite"ly, adv. -- Im`po*lite"ness, n.
Shades of meaning
Fernald has no entry of its own for impolite; he lists it under bluff.
He lists it without comment; the entries above explain its neighbors.