The Collaborative International Dictionary of English v.0.48:
Aster \As"ter\ ([a^]s"t[~e]r), n. [L. aster aster, star, Gr.
'asth`r star. See Star.]
1. (Bot.) A genus of herbs with compound white or bluish
flowers; starwort; Michaelmas daisy.
2. (Floriculture) A plant of the genus Callistephus. Many
varieties (called China asters, German asters, etc.)
are cultivated for their handsome compound flowers.
3. (Biol.) A star-shaped figure of achromatic substance found
chiefly in cells dividing by mitosis.
[Webster 1913 Suppl.]