/ Thesaurus / P Synonyms of presenile dementia Find synonyms for: Noun1. presenile dementia, dementia, dementednessusage: dementia with onset before the age of 65WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: bibliophile Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language