‖Ep′i‐ster″num (?), n.; pl.Episterna (#). [NL. See Epi-, and Sternum.] 1. (Anat.) (a) A median bone connected with the sternum, in many vertebrates; the interclavicle. (b) Same as Epiplastron.
2. (Zoöl.) One of the lateral pieces next to the sternum in the thorax of insects.