momentary

/ˌmoʊmənˈtɛri/

/ˈmʌʊmɪntɛri/

Something that lasts for a very short time is momentary. A flash of lightning is momentary, since it blazes across the sky for only a second or two.

Use the adjective momentary when you want to describe something brief or fleeting, like a momentary pause in a speech or a momentary flash of insight that pops into your head and disappears. If it lasts just a moment, it's momentary. The root word is the Latin momentarius, "of brief duration," which in turn comes from momentum, "short time, or instant."

Definitions of momentary

1. adjective

   lasting for a markedly brief time
   “a momentary glimpse”

   synonyms: fleeting, fugitive, momentaneous

   short

   primarily temporal sense; indicating or being or seeming to be limited in duration