From Longman Dictionary of Contemporary Englishsinfulsin‧ful /ˈsɪnfəl/ adjective 1 RRBAD BEHAVIOUR OR ACTIONSagainst religious rules, or doing something that is against religious rules → wicked Dancing was believed to be sinful. a wicked, sinful man2 BADvery wrong or bad a sinful waste of taxpayers’ money —sinfully adverb
Examples from the Corpus
sinful• The context was always a plea for tolerance of something which he had been taught to regard as sinful.• They were not just inconvenient and disruptive, but sinful.• We are both exalted and fallen at the same time: sinful and yet given unique status in the universe of things.• sinful behavior• They believe that humans are sinful by nature.• When she declined his advances, he entrusted her to a matron of a sinful house.• Veal marsala is a sinful pleasure that I allow myself only a few times in a decade.• Though the sinful propensities remain in us till our dying day, they need not be dominant.• Therefore, it was not sinful to exploit the poor. 