1. Printing. Three asterisks in a triangular formation used to call attention to a following passage.
2. Astronomy. A cluster of stars smaller than a constellation.
3. Mineralogy. A six-rayed starlike figure optically produced in some crystal structures by reflected or transmitted light.

[Greek asterismos, constellation, from astēr, star.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.