Entry 1 sense Webster, 1913 Phæospore · Phæ·o·spore · IPA 01 n. A brownish zoospore, characteristic of an order (Phæosporeæ) of dark green or olive-colored algæ. 1. A brownish zoospore, characteristic of an order (Phæosporeæ) of dark green or olive-colored algæ.(Bot.)