/ Dictionary / Index S simpleminded: Meaning and Definition of Find definitions for: sim•ple•mind•ed Pronunciation: (sim'pul-mīn'did, -mīn"-), [key] — adj. free of deceit or guile; artless or unsophisticated. lacking in mental acuteness or sense. mentally deficient. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. simple microscope simple pendulum Related Content Daily Word Quiz: denizen Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language