/ Dictionary / Index I islet: Meaning and Definition of Find definitions for: is•let Pronunciation: (ī'lit), [key] — n. a very small island. —adj. situated in or pertaining to the islet of Langerhans: islet cells. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: islet (Thesaurus) Isle Royale islet cell adenoma Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language