Seyfert galaxy: Meaning and Definition of

Sey'fert gal"axy

Pronunciation: (sī'furt, sē'-), [key]
— Astron. Astron.
  1. one of a group of spiral galaxies with compact, bright nuclei having characteristically broad emission lines suggestive of very hot gases in violent motion at the center.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.