uranylPronunciation: /ˈjʊər(ə)nʌɪl, ˈjʊər(ə)nɪl/Definition of uranyl noun [as modifier] Chemistry the cation UO22+, present in some compounds of uranium:uranyl acetateOrigin: mid 19th century: from uranium + -yluranyl in other Oxford dictionaries Definition of uranyl in the US English dictionary