/ Dictionary / Index S seiche: Meaning and Definition of Find definitions for: seiche Pronunciation: (sāsh), [key] — n. an occasional and sudden oscillation of the water of a lake, bay, estuary, etc., producing fluctuations in the water level and caused by wind, earthquakes, changes in barometric pressure, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: seiche (Thesaurus) seicento seidel Related Content Daily Word Quiz: resilient Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language