A small asexual spore that develops inside the cell of some bacteria and algae

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1859, perhaps from French, from endo- + spore .

WordNet Word definitions in WordNet
n. a small asexual spore that develops inside the cell of some bacteria and algae

Wiktionary Word definitions in Wiktionary
n. 1 The inner layer of a spore 2 A small vegetative spore produced by some bacteria

Wikipedia Word definitions in Wikipedia
An endospore is a dormant , tough, and non-reproductive structure produced by certain bacteria from the Firmicute phylum. The name "endospore" is suggestive of a spore or seed-like form ( endo means within), but it is not a true spore (i.e., not an offspring). ...

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Endospore \En"do*spore\, n. [Endo- + spore.] (Bot.) The thin inner coat of certain spores.