ex·pres·sio uni·us est ex·clu·sio al·te·ri·us \ekˈspresēˌōˈünēˌu̇ˌseˌstekˈsklüsēˌōˌälˈterēˌu̇s\ Etymology: New Latin, expression of the one is exclusion of the other : a principle in law: when one or more things of a class are expressly mentioned others of the same class are excluded