incorrigible
Concise Oxford English Dictionary © 2008 Oxford University Press:
incorrigible /ɪnˈkɒrɪdʒɪb(ə)l/
▶adjective not able to be corrected or reformed: she's an incorrigible flirt.
– derivatives
incorrigibility noun,
incorrigibly adverb.
incorrigibility noun,
incorrigibly adverb.
'incorrigible' also found in these Oxford entries:

