1.past simple and past participle of sicken
2.to become ill
The child sickened and died.
"You look feverish. Are you sickening for (= about to become ill with) something?"
3.to cause someone to feel unpleasant emotions, especially anger and shock
The violence in the film sickened me.
He was sickened by/at the number of people who were hurt in the crash.