Is it farther or further?
1879, American English, "one working under supervision as part of professional training," especially "doctor in training in a hospital," from French interne "assistant doctor," literally "resident within a school," from Middle French interne "internal" (see intern (v.)). The verb in this sense is attested from 1933. Related: Interned; interning.
intern in·tern or in·terne (ĭn'tûrn')
An advanced student or recent graduate who assists in the medical or surgical care of hospital patients and who resides within that institution. v. in·terned, in·tern·ing, in·terns
To train or to serve as an intern.