[ meg-uh-spawr, -spohr ]
/ ˈmɛg əˌspɔr, -ˌspoʊr /

noun Botany.

the larger of the two kinds of spores characteristically produced by seed plants and a few fern allies, developing into a female gametophyte.Compare microspore.
the embryo sac of a flowering plant.

Origin of megaspore

First recorded in 1885–90; mega- + spore
Also called macrospore.

Related forms

meg·a·spor·ic [meg-uh-spawr-ik, -spor-] /ˌmɛg əˈspɔr ɪk, -ˈspɒr-/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for megaspore

British Dictionary definitions for megaspore


/ (ˈmɛɡəˌspɔː) /


Also called: macrospore the larger of the two types of spore produced by some spore-bearing plants, which develops into the female gametophyteCompare microspore (def. 1)
the cell in flowering plants that gives rise to the embryo sac

Derived Forms

megasporic, adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for megaspore


[ mĕgə-spôr ]

One of the two types of haploid spores produced by a heterosporous plant. Megaspores develop into female gametophytes and are usually larger than microspores.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.