C2 adjective /ɪnˈkɒrɪdʒəbəl/
incorrigible
訂正不可能な
Meaning
incapable of being corrected, improved, or reformed
Example
He is an incorrigible optimist who never loses hope.
彼は決して希望を失わない訂正不可能な楽観主義者です。