/ Dictionary / Index S sunspot cycle: Meaning and Definition of Find definitions for: sun'spot cy"cle Pronunciation: [key] — Astron. Astron. the cycle, averaging in duration slightly more than 11 years, in which the frequency of sunspots varies from a maximum to a minimum and back to a maximum again. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sunspot sunspot number Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language