/ Dictionary / Index S supergranulation cell: Meaning and Definition of Find definitions for: su•per•gran•u•la'tion cell" Pronunciation: (s"pur-gran"yu-lā'shun), [key] — Astron. Astron. one of a number of large convection cells in the photosphere and chromosphere of the sun, each having a diameter of 10,000–20,000 mi. (16,000–32,000 km) and lasting longer than a day. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. supergrade supergraphics Related Content Daily Word Quiz: menagerie Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language