say it: MOH-muhn-ter-ee
momentary is an adjective meaning "lasting for a markedly brief time". It carries one recorded sense.
lasting for a markedly brief time
“a fleeting glance”
“fugitive hours”
“rapid momentaneous association of things that meet and pass”
“a momentary glimpse”
Definitions, synonyms and semantic relations for momentary come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.