Antonyms of adj discourteous

2 senses of discourteous

Sense 1
discourteous (vs. courteous) -- (showing no courtesy; rude; "a distant and at times discourteous young")

courteous (vs. discourteous) -- (characterized by courtesy and gracious good manners; "if a man be gracious and courteous to strangers it shows he is a citizen of the world"-Francis Bacon)
        => chivalrous, gallant, knightly -- (being attentive to women like an ideal knight)

Sense 2
discourteous, ungracious -- (lacking social graces)

INDIRECT (VIA impolite) -> polite -- (showing regard for others in manners, speech, behavior, etc.)

Similarity of adj discourteous

2 senses of discourteous

Sense 1
discourteous (vs. courteous) -- (showing no courtesy; rude; "a distant and at times discourteous young")
       => abrupt -- (surprisingly and unceremoniously brusque in manner; "an abrupt reply")
       => brusque, brusk, curt, short (predicate) -- (marked by rude or peremptory shortness; "try to cultivate a less brusque manner"; "a curt reply"; "the salesgirl was very short with him")
       => caddish, unchivalrous, ungallant -- (offensively discourteous)
       => unceremonious -- (without due formalities; "unceremonious dismissal from office")
          Also See-> disrespectful#1

Sense 2
discourteous, ungracious -- (lacking social graces)
       => impolite (vs. polite) -- (not polite)