Definition of unmomentous in US English:

unmomentous

adjective

  • Of no great weight or consequence; unimportant.

Origin

Mid 18th century; earliest use found in Patrick Delany (?1686–1768), Church of Ireland dean of Down and writer. From un- + momentous.

Pronunciation

unmomentous

/(ˌ)ʌnməˈmɛntəs/