WWordGenerator.org GeneratorsWord ListsBlogAboutGenerate a word Home / R / rule of thumb rule of thumb noun 13 letters Scrabble 21 WWF 25 Definitions noun a rule or principle that provides guidance to appropriate behavior guidelineguidepost Look “rule of thumb” up elsewhere Wiktionary ↗ Merriam-Webster ↗ Etymonline ↗ Dictionary.com ↗ Want another word?Spin the dictionary for a fresh one. Generate a word →