the state of being ill [= illness]:
an insurance policy against long-term sickness and injury
working days lost due to sickness
the feeling that you are about to bring up food from your stomach, or the act of bringing food up [= nausea] ➔ morning sickness, sleeping sickness
travel/motion/car/sea etc sickness (=sickness that some people get while travelling)
Liam had suffered violent sickness and diarrhoea.
a particular illness:
4 [uncountable and countable]
the serious problems and weaknesses of a social, political, or economic system:
He said the idea of 'success' was part of the sickness of Western cultures.