WWordGenerator.org GeneratorsWord ListsBlogAboutGenerate a word Home / A / atomic number 18 atomic number 18 noun 16 letters Scrabble 20 WWF 26 Definitions noun a colorless and odorless inert gas; one of the six inert gases; comprises approximately 1% of the earth's atmosphere arargon Look “atomic number 18” up elsewhere Wiktionary ↗ Merriam-Webster ↗ Etymonline ↗ Dictionary.com ↗ Want another word?Spin the dictionary for a fresh one. Generate a word →