Fly-by-night is a term used to describe someone or something that is UNRELIABLE, SHADY, and TRANSIENT. The crossword solutions for this term include MOTH (4 letters), OWL (3 letters), REDEYE (6 letters), BAT (3 letters), TRANSIENT (9 letters), SHADY (5 letters), UNRELIABLE (10 letters), SUSPECT (7 letters), and ELOPE (5 letters). Moths, owls, bats, and redeyes are all nocturnal creatures, which could be used to symbolize the idea of being secretive or elusive. TRANSIENT and ELOPE both suggest a sense of movement or escape, while SHADY and SUSPECT imply a lack of trustworthiness. UNRELIABLE is the most direct of the words, and it serves as a reminder that fly-by-night people or things should not be trusted.