Incorrigible is an Adjective
Difficult to manage, control, amend or reform
Firmly rooted (like wrong habits)
Noun form: Incorrigibleness
Adverb : Incorrigibly
1.The teacher's incorrigible habit of caning students was met with much criticism.
2. Incorrigible drunk drivers should be given the harshest punishment.
3. The incorrigible child could never be taught to sit quietly in class.