1. Any of various plants of the genus Aster or closely related genera in the composite family, having radiate flower heads with white, pink, or violet rays and usually a yellow disk.
2. The China aster.
3. Biology A star-shaped structure formed in the cytoplasm of an animal cell during mitosis, having raylike microtubules that surround the centrosome.
[Latin astēr, a type of plant, from Greek, star, type of daisy; see ster-3 in the Appendix of Indo-European roots.]
(click for a larger image)aster
European Michaelmas daisies
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.