- a silken case or capsule containing eggs of a female spider.
Also called egg case.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for egg sac
In the specimen figured, the egg-sac was concealed in the upper part of the web.
In a spider's egg-sac the young after hatching do not immediately leave the sac, but remain in it for several days.Elementary Zoology, Second Edition
Vernon L. Kellogg
These eggs hatch early in the winter; but no spiders emerge from the egg-sac until the following spring.
One of the running spiders (Dolomedes) carries her egg-sac with her mandibles until the young are ready to emerge.
- The silken pouch in which many spiders deposit their eggs. Also called egg case
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.