/ Thesaurus / L Synonyms of louisiana purchase Find synonyms for: Noun1. Louisiana Purchaseusage: territory in the western United States purchased from France in 1803 for $15 million; extends from the Mississippi River to the Rocky Mountains and from the Gulf of Mexico to CanadaWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: dormant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language