/ Thesaurus / L Synonyms of letters of administration Find synonyms for: Noun1. letters of administration, legal document, legal instrument, official document, instrumentusage: legal document naming someone to administer an estate when no executor has been namedWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language