/ Dictionary / Index D dunder: Meaning and Definition of Find definitions for: dun•der Pronunciation: (dun'dur), [key] — n. the thick lees from boiled sugar-cane juice used in the distillation of rum. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Dundee dunderhead Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language