methyl met·hyl UK/ˈmɛθaɪl/ US/ˈmɛθɪl/ uncommon noun 1. the univalent radical CH3- derived from methane Synonymsmethyl groupmethyl radical Related words Word family methylenemethylatedmethylated spiritmethylbenzenemethyldopamethylenedioxymethamphetaminemethylene bluemethylene chloridemethylene groupmethylene radicalmethylphenidatemethyltestosteronemethylthionine chloridemethyl alcoholmethyl bromidemethyl ethyl ketone Broader terms alkyl Narrower terms aminomethanehydroxymethyl WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.