As`ter*ism (&?;), n. [Gr. &?;, fr. 'asth`r star; cf. F. astérisme.] 1. (Astron.) (a) A constellation. [Obs.] (b) A small cluster of stars.

2. (Printing) (a) An asterisk, or mark of reference. [R.] (b) Three asterisks placed in this manner, &asterism;, to direct attention to a particular passage.

3. (Crystallog.) An optical property of some crystals which exhibit a star-shaped by reflected light, as star sapphire, or by transmitted light, as some mica.

• a small group of stars
  
• a star-shaped figure exhibited by some crystals by reflected light (as in a star sapphire) or by transmitted light (as in some mica)