zygotoblasthttp://www.oed.com/dictionary/zygotoblast_n%3Ftab%3Dmeaning_and_usezygotoblast, n.
First published 1921; not fully revised

zygotoblastnoun

Biology.
  1. 1899–
    One of a number of germ-cells or sporozoites produced by budding from a zygotomere (see below).
    Stressed as zyˈgotoblast.
    1. 1899

Originally published as part of the entry for zygote, n.

zygote, n. was first published in 1921; not fully revised.