Breadcrumb Home > Thesaurus > P Synonyms of prn Find synonyms for: Adverb 1. as needed, as required, pro re nata, PRN usage: according to need (physicians use PRN in writing prescriptions); "add water as needed" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of prn (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: parallax Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language