Source : WordNet®

miosis
     n 1: (genetics) cell division that produces reproductive cells in
          sexually reproducing organisms; the nucleus divides into
          four nuclei each containing half the chromosome number
          (leading to gametes in animals and spores in plants)
          [syn: {meiosis}, {reduction division}]
     2: reflex contraction of the sphincter muscle of the iris in
        response to a bright light (or certain drugs) causing the
        pupil to become smaller [syn: {light reflex}, {pupillary
        reflex}, {myosis}]
     [also: {mioses} (pl)]