Definition of "megaspore" []

• The larger of two types of spores that give rise to a female gametophyte. Also called macrospore. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "This one haploid cell, the megaspore, then undergoes three successive mitoses to form the embryo sac, or the female gametopyhte."
• "The behaviour of the chromosomes in meiosis or reduction division both in the pollen mother-cells and in the megaspore mother-cells which give rise to the so-called embryo-sac are fully described by Gates."
• "Female cone develops two ovules on the upper surface of each cone scale; each ovule contains haploid megaspore."