Pronunciation: (as'tur), [key]
1. any composite plant of the genus Aster, having rays varying from white or pink to blue around a yellow disk.
2. a plant of some allied genus, as the China aster.
3. Cell Biol.a structure formed in a cell during mitosis, composed of astral rays radiating about the centrosome.
4. Furniture. sunflower (def. 2).
a diminutive or pejorative suffix denoting something that imperfectly resembles or mimics the true thing: criticaster; poetaster, oleaster.
Chiefly Biol.a combining form with the meaning “star,” used in the formation of compound words: diaster.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.