A2physically or mentally ill; not well or healthy: a sick childa sick cowMy father has been off sick (= not working because of illness) for a long time.Anyone who could hurt a child like that must be sick (= mentally ill).The old woman fell/took/was taken sick (= became ill) while she was away and had to come home.Sarah called in/reported sick (= told her employer that she was unable to go to work because of illness).figurativeHigh rates of crime are considered by some people to be a sign of a sick society.→ See alsoheartsick, homesick, lovesickNot fit and healthyThin or slender (of people)