in ‧ ter ‧ nal ‧ ize AC BrE AmE ( also internalise British English ) /ɪnˈtɜːnəlaɪz $ -ɜːr-/ verb [transitive]
if you internalize a particular belief, attitude, behaviour etc, it becomes part of your character
—internalization /ɪnˌtɜːnəlaɪˈzeɪʃ ə n $ ɪnˌtɜːrnələ-/ noun [uncountable]