naphthyl
/ˈnafθʌɪl/ /ˈnapθʌɪl/ /ˈnafθ(ɪ)l/(also naphtyl) Chemistry
noun
Either of two isomeric monovalent radicals, C10H7, derived from naphthalene. Usually attributive or as a formative in chemical names.
Origin
Mid 19th century; earliest use found in Proceedings of the Royal Society of London. From naphth- + -yl. With form naphtyl perhaps compare French naphtyl-, combining form, naphtyle, noun.