Crossword clue: the contents or substance of the ovum; egg yolk. see illust. of ovum. 2. (bot.) perisperm in an early condition.
1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).
Possible answers
nutritive material of an ovum stored for the nutrition of an embryo (especially the yellow mass of a bird or reptile egg