Definition of Ephemeroptera in US English:

Ephemeroptera

plural noun

Entomology
  • 1An order of insects that comprises the mayflies.

    • ‘We further included four representatives of the Zygoptera, one representative of the Epiophlebiidae, and one representative of the Ephemeroptera of the family Ephemeridae as outgroup taxa.’
    1. 1.1as plural noun ephemeroptera Insects of the order Ephemeroptera; mayflies.

Origin

Modern Latin (plural), from Ephemera (genus name) + pteron ‘wing’.

Pronunciation

Ephemeroptera

/əˌfeməˈräptərə/