Someone who is ill is suffering from a disease or a health problem.
In November 1941 Payne was seriously ill with pneumonia.
1941年11月,佩恩患了严重的肺炎。
You can use ill in front of some nouns to indicate that you are referring to something harmful or unpleasant.
She had brought ill luck into her family.
她给家庭带来了厄运。
Ill means the same as 'badly'.
The company's conservative instincts sit ill with competition.
该公司的保守本性不适合竞争。
ills
People who are ill in some way can be referred to as, for example, the mentally ill.
The hospice provides care for the terminally ill.
救济院为身患绝症的人们提供护理。
Difficulties and problems are sometimes referred to as ills.
His critics maintain that he's responsible for many of Algeria's ills.
他的批评者坚持认为他对阿尔及利亚的许多问题负有责任。
Ill is evil or harm.
They say they mean you no ill.
他们说他们对你没有恶意。
fall ill , be taken ill
If you fall ill or are taken ill, you suddenly become ill.
Shortly before Christmas, he was mysteriously taken ill.
圣诞节前不久,他突然莫名其妙地病倒了。
can ill afford
If you say that someone can ill afford to do something, or can ill afford something, you mean that they must prevent it from happening because it would be harmful or embarrassing to them.
It's possible he won't play but I can ill afford to lose him.
他有可能不会出场,但我难以承受失去他的损失。