The difference between Fugacious and Transient

When used as adjectives, fugacious means fleeting, fading quickly, transient, whereas transient means passing or disappearing with time.

Transient is also noun with the meaning: something which is transient.

check bellow for the other definitions of Fugacious and Transient

Transient as an adjective:

Passing or disappearing with time; transitory.

Examples:

"a transient pleasure"
Transient as an adjective:

Remaining for only a brief time.

Examples:

"a transient view of a landscape"

"a transient disease"
Transient as an adjective (physics):

Decaying with time, especially exponentially.
Transient as an adjective (mathematics, stochastic processes, of a [[state]]):

having a positive probability of being left and never being visited again.
Transient as an adjective:

Occasional; isolated; one-off
Transient as an adjective:

Passing through; passing from one person to another.
Transient as an adjective (music):

Intermediate.
Transient as an adjective (philosophy):

Operating beyond itself; having an external effect.

Transient as a noun:

Something which is transient.
Transient as a noun (physics):

A transient phenomenon, especially an electric current; a very brief surge.
Transient as a noun (acoustics):

A relatively loud, non-repeating signal in an audio waveform which occurs very quickly, such as the attack of a snare drum.
Transient as a noun:

A person who passes through a place for a short time; a traveller; a migrant worker
Transient as a noun:

An unhoused person