Breadcrumb Home > Dictionary > Index S Seyfert galaxy: Meaning and Definition of Find definitions for: Sey'fert gal"axy Pronunciation: (sī'furt, sē'-), [key] — Astron. Astron. 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. Seychellois Seyhan ✖ Related Content Daily Word Quiz: guilloche Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language