illicit
Meaning: forbidden, not permitted
Usage: The fourth-grader learned many illicit words from a pamphlet that was being passed around school.
incorrigible
Meaning: incapable of correction, delinquent
Usage: Even after several warnings, the incorrigible student kept interrupting the class.
insidious
Meaning: appealing but imperceptibly harmful, seductive
Usage: Lisa’s insidious chocolate cake tastes so good but makes you feel so sick later on!
licentious
Meaning: displaying a lack of moral or legal restraints
Usage: The licentious ruler ignored every law meant to restrain his behavior.
flagrant
Meaning: offensive, egregious
Usage: The judge’s decision to set the man free simply because that man was his brother was a flagrant abuse of power.