Discourteous (; see Courteous, 277), a.
Etymology: [Pref. dis- + courteous: cf. OF. discortois.]
Uncivil; rude; wanting in courtesy or good manners; uncourteous. -- Dis*cour"te*ous*ly, adv. -- Dis*cour"te*ous*ness, n.
Shades of meaning
Fernald has no entry of its own for discourteous; he lists it under bluff.
He lists it without comment; the entries above explain its neighbors.