Epoxides derived from arenes by 1,2-addition of an oxygen atom to a formal double bond, e.g. 5,6-epoxycyclohexa-1,3-diene.
(Common usage has extended the term to include examples with the epoxy group bridging nonadjacent atoms.)
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1318 (https://doi.org/10.1351/pac199567081307)