/ Thesaurus / K Synonyms of keystone state Find synonyms for: Noun1. Pennsylvania, Keystone State, PAusage: a Mid-Atlantic state; one of the original 13 coloniesWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: heifer Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language