Synonyms and related words :
acid, ailing, angry, bad, below par, caustic, cheerless, corrosive, critically ill, discontented, down, faint, faintish, feeling awful, feeling evil, feeling faint, feeling something terrible, grim, humorless, ill, in bad humor, in danger, indisposed, infestive, joyless, laid low, mirthless, miserable, mortally ill, not quite right, off-color, out of humor, out of temper, pleasureless, rocky, seedy, sick, sick unto death, sickish, sorry, sorryish, taken ill, uncheerful, uncheery, under the weather, unhappy, unjoyful, unmirthful, unsmiling, unwell, wretched