an anxiety disorder characterized by extreme and irrational fear of simple things or social situations; "phobic disorder is a general term for all phobias"
any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention
the quality of lacking any predictable order or plan
(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work; "entropy increases as matter and energy in the universe degrade to an ultimate state of inert uniformity"