diplo-

Double.

Greek diplous, double.

A diplococcus (Greek kokkos, berry) is a roughly spherical bacterium that occurs in pairs, such as pneumococcus; diplopia (Greek ōps, ōp-, eye) is the technical term for double vision; a cell that is diploid contains two complete sets of chromosomes, one from each parent; a diplontic alga or other lower plant has a life cycle in which the main form is diploid. Diploma derives from the Greek word for a folded paper, hence an official document; diplomat comes from the same source (somebody who carries state papers).