1.
boorish, uncouth, unrefined, insensitive to social graces
Lacking refinement, elegance, or understanding of social subtleties. Describes someone or something that is tactless, unpolished, or fails to appreciate the finer points of a situation.
Adjective type: Na-adjective. Uses な before nouns: 無粋な質問.
Etymology: 無 (without) + 粋 (refined elegance, chic)
Nuance: 無粋 implies a lack of sensitivity to atmosphere, mood, or social graces. It's often used self-deprecatingly when about to do something that might spoil the mood or violate social conventions.