between or among nations / participated in by two or more nations / common to, or affecting, two or more nations. / serving two or more nations

(sports) Someone who has represented their country in a particular sport. / (sports) A game or contest between two or more nations.

A make of truck and other vehicles formerly manufactured by International Harvester.

Confinement within narrow limits, as of foreign troops, to the interior of a country.

(medicine) Within the body. / Concerned with the domestic affairs of a nation, state or other political community. / Concerned with the non-public affairs of a company or other organisation.

To process new information in one's mind. / To refrain from expressing (a negative emotion), to one's psychological detriment; to bottle up.

A person who is interned, forcibly or voluntarily.

(transitive) To imprison somebody, usually without trial.

(archaic) Internal.

A student or recent graduate who works in order to gain experience in their chosen field. / A medical student or recent graduate working in a hospital as a final part of medical training.