- fly-by-night
- adj1. unreliable, irresponsible, unstable, unsteady, inconstant; disreputable, discreditable, dishonorable; shifty, shady, sharp, jackleg, dishonest, crooked.2. brief, momentary, transitory, ephemeral, shortlived; impermanent, not lasting, like the shifting sands; transient, fleeting, Inf. here-today-gone-tomorrow.n3. bad credit risk, debt-skipper, Sl. welsher, check-bouncer; confidence man, Inf. con man, swindler, fleecer.
A Note on the Style of the synonym finder. 2014.