tetraspore

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. One of four spores produced from a tetrasporangium.

Century Dictionary and Cyclopedia

1. n. In botany, an asexually produced spore of florideous algæ: so called from the circumstance that usually four are produced by the division of the mother-cell. See spore, cruciate, 2, bispore, Florideæ. Also called spherospore. See cut under Algæ.

Wiktionary

1. n. biology Any of the four, asexual spores produced by a sporangium

GNU Webster's 1913

1. n. (Bot.) A nonsexual spore, one of a group of four regularly occurring in red seaweeds.

WordNet 3.0

1. n. one of the four asexual spores produced within a sporangium