IPA: /ɔːrˈdɪəl/
KK: /ɔrˈdil/
A very difficult or painful experience that tests a person's character or endurance.
Going through the surgery was a real ordeal for her.
Ordeal comes from Old English 'ordēale', which is a combination of 'ord' (meaning trial or test) and 'dǣl' (meaning portion or part). The word originally referred to a trial or test that one had to undergo, often with a divine element involved.
Think of 'trial' ('ord') and 'portion' ('dǣl') to remember that an ordeal is a challenging test or trial one must face.