Compounds derived from tertiary amines by the attachment of one oxygen atom to the nitrogen atom
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1316 (https://doi.org/10.1351/pac199567081307)
. By extension the term includes the analogous derivatives of primary and secondary amines.