/ Dictionary / Index O oligophrenia: Meaning and Definition of Find definitions for: ol•i•go•phre•ni•a Pronunciation: (ol"i-gō-frē'nē-u, u-lig"u-), [key] — n. Pathol. less than normal mental development. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. oligonucleotide oligopoly Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language