Internal.
To put for safe keeping in the interior of a place or country; to confine to one locality; as, to intern troops which have fled for refuge to a neutral country.
To hold until the end of a war, as enemy citizens in a country at the time of outbreak of hostilities; - an action performed by countries.
A resident physician in a hospital, especially one who has recently received the Doctorate and is practising under supervision of experienced physicians, as a continuation of the training process; a house physician; also called houseman in Britain.
A person working as an apprentice to gain experience in an occupation; sometimes the position is paid a salary, and other times it is not; as, a white house intern; an intern in a law firm.