momentary

momentary
mo‧men‧ta‧ry /ˈməʊməntəri $ ˈmoʊmənteri/ adjectivecontinuing for a very short time
   SYN  brief:
    There was a momentary pause.
     

THESAURUS

■ time
   ▪ short not long: I lived in Tokyo for a short time. | Smokers have a shorter life expectancy than non-smokers.
   ▪ brief especially written lasting only for a short time. Brief is more formal than short, and is used especially in written English: The President will make a brief visit to Seattle today. | He coached Hingis for a brief period in the 1990s.
   ▪ quick [only before noun] taking a short time to do something: I had a quick look at the map. | He had a quick shower and then went out.
   ▪ short-lived lasting only for a short time – used especially when someone wishes that a good situation had been able to last for longer: short-lived success | The ceasefire was short-lived. | a short-lived romance | short-lived optimism about the economy
   ▪ fleeting lasting only for an extremely short time – used especially when someone wishes that something had been able to last for longer: a fleeting visit | a fleeting smile | She caught a fleeting glimpse of him. | a fleeting moment of happiness | a fleeting thought
   ▪ momentary lasting for a very short time – used especially about feelings or pauses: There was a momentary pause in the conversation. | The momentary panic ended when he found his two-year-old son waiting happily outside the store.
   ▪ passing [only before noun] lasting only for a short time – used especially when people are only interested in something or mention something for a short time: passing fashions | He made only a passing reference to war. | It’s just a passing phase (=it will end soon).
   ▪ ephemeral formal lasting only for a short time, and ending quickly like everything else in this world: Beauty is ephemeral. | the ephemeral nature of our existence | His wealth proved to be ephemeral.