Illest

adjective

1. Evil; wicked (of people).
2. Morally reprehensible (of behaviour etc.); blameworthy.
3. Indicative of unkind or malevolent intentions; harsh, cruel.

   "He suffered from ill treatment."

4. Unpropitious, unkind, faulty, not up to reasonable standard.

   "ill manners; ill will"

5. Unwell in terms of health or physical condition; sick.

   "I've been ill with the flu for the past few days."