n. [ Gr. me`ros part + -blast. ] (Biol.) An ovum, as that of a mammal, only partially composed of germinal matter, that is, consisting of both a germinal portion and an albuminous or nutritive one; -- opposed to holoblast. [ 1913 Webster ]

a. (Biol.) Consisting only in part of germinal matter; characterized by partial segmentation only; as, meroblastic ova, in which a portion of the yolk only undergoes fission; meroblastic segmentation; -- opposed to holoblastic. [ 1913 Webster ]