Definitions of transient:

  • noun:   (physics) a short-lived oscillation in a system caused by a sudden change of voltage or current or load
  • noun:   one who stays for only a short time
    Example: "Transient laborers"
  • adjective:   of a mental act; causing effects outside the mind
  • adjective:   enduring a very short time
    Example: "Youth's transient beauty"