Why can the common name ethyl ether also mean diethyl ether?

The common name "ethyl ether" is used to refer to diethyl ether due to the conventions of chemical nomenclature for ethers. When naming ethers, the two alkyl groups bonded to the oxygen atom are typically listed; however, if only one alkyl group is specified in the name, it implies that both groups are identical.1

Because diethyl ether consists of two ethyl groups linked through an oxygen atom, the name "ethyl ether" serves as a shorthand to describe this specific structure. While systematic IUPAC nomenclature identifies the compound as ethoxyethane, the common name remains widely recognized in scientific and historical contexts, particularly given the compound's long-standing use as a surgical anesthetic.213