sinful
adj.adj. wrong or bad according to religious rules. You can also use it to describe something that is so delicious or enjoyable that you feel a little guilty about it.
adj. violating religious or moral laws; wicked. In informal contexts, it describes something intensely pleasurable or indulgent that evokes a sense of guilt.
The chocolate cake looked absolutely sinful.
Many people believe that lying is a sinful act that harms the soul.
The dessert menu featured a sinful combination of dark chocolate and salted caramel that few diners could resist despite their dietary resolutions.
From Middle English synful, senful, sunful, from Old English synful (“sinful, guilty, wicked, corrupt”), equivalent to sin + -ful. Compare Dutch zondevol (“sinful”), German sündevoll (“sinful”), Danish syndefuld (“sinful”), Swedish syndfull (“sinful”), Icelandic syndfullur (“sinful”).
Often used in a lighthearted, hyperbolic way to describe rich food or luxury.