中央的,中间的
Mesial \Me"sial\ (?; 277), a. [Gr. ? middle.] (Anat.) Middle; median; in, or in the region of, the mesial plane; internal; -- opposed to {lateral}. {Mesial plane}. (Anat.) See {Meson}.
mesial adj : being in or directed toward the midline or mesial plane of the body [ant: {distal}]