unhealthy, ailing, diseased, afflicted. Ill, sick mean being in bad health, not being well. Ill is the more formal word. In the U.S. the two words are used practically interchangeably except that sick is always used when the word modifies the following noun: He looks sick
); a sick person.
In England, sick is not interchangeable with ill, but usually has the connotation of nauseous: She got sick and threw up.
sick, however, is used before nouns just as in the U.S.: a sick man. 4.
wrong, iniquitous. See bad1
hurt, pain, affliction, misery. 9.
illness, affliction. 13.