#1 Fleeting
Describes something that passes by very quickly, lasting for only a very brief period of time, like a fleeting glimpse or moment.
#2 Transient
Refers to things that are impermanent and last only for a short time, often used for phenomena or states that are not stable or lasting.
#3 Evanescent
Suggests something that is soon passing out of sight, memory, or existence; quickly fading or disappearing, like a rainbow.
#4 Momentary
Indicates something that lasts for only a moment; very brief, emphasizing the extremely short duration of an event or feeling.
#5 Short-lived
Clearly denotes anything that lasts for only a short period of time, straightforwardly indicating its non-enduring nature.