A paid personal day intended to be used due to illness either for recuperation or medical treatment.

hitman, hired killer (especially when referring to Latin American drug cartels)

(medicine) A disease characterized by sickle-shaped red blood cells.

(Canada, US) A disease characterized by sickle-shaped red blood cells.

(archaic) Epilepsy.

Used other than figuratively or idiomatically: be sick. / (informal) To vomit.

(historical) A curved dagger used in Ancient Roman times, associated with the Thracian and Illyrians, gladiators, and Sicarii.

Paid absence from work specifically to recover from illness.

Alternative spelling of homesickness

(chiefly US) Nauseated, queasy or vomiting, sick.