society > morality > moral evil > licentiousness > moral or spiritual impurity > indecency > [adjective] > extremely (4)
Highly offensive or loathsome, esp. morally; evil, abominable, foul. In later use: esp. (of language, behaviour, etc.) grossly coarse or indecent…
Extremely coarse in behaviour or morals; brutally lacking in refinement or decency. of persons.
The sense ‘gross, indelicate’ passes into that of ‘indecent, obscene’. (Chiefly of language.)