sinfully

Sinfully is an adverb derived from the adjective sinful. It describes an action, behavior, or quality that is performed or perceived in a morally wrong, disobedient, or transgressive manner, often with a sense of indulgence or pleasure. The form originates from Old English synful, from syn (sin) and the suffix -ful, and has cognates in other Germanic languages.

In modern English, sinfully is frequently used in figurative or rhetorical contexts to intensify descriptions of enjoyment, temptation, or vice, rather than to make a literal religious accusation. It can convey a cheeky or indulgent tone when describing experiences or preferences that feel morally questionable only in a playful sense. Examples include phrases such as sinfully rich, sinfully easy, or sinfully smooth, where the adverb strengthens the sense of luxurious excess or effortless desirability.

Usage notes indicate that sinfully is common in literary, pop culture, and conversational speech, where it often carries a light, provocative nuance. In formal writing, it may be considered informal or sensational, depending on context and audience, and writers sometimes choose more precise terms if a neutral register is required.

See also: sinful, sin, morality, temptation.