bad 含义广泛，指任何不好的或不合需要的品质。
evil 语气比bad强，强调道德上的邪恶不良，含狡猾凶险或危害他人的意味。
ill 与evil意义接近，但语气弱一些，常指道德或性质方面的不良。
poor 普通用词，侧重指事物的质量或数量低于标准或不合要求。用于指天气与食品时可与bad通用。
wicked 语气比evil强，指居心叵测，任意违反道德标准，有意作恶。
参考例句
1. The man was very ill, but he survived. 这个人病得很厉害，可是他活下来。
2. I mean you no ill. 我的意思是你没有病。
3. Is your wife ill? 是你太太病了吗?
英英解释
n.
1. an often persistent bodily disorder or disease; a cause for complaining
2. affected by an impairment of normal physical or mental function
3. resulting in suffering or adversity
4. distressing
5. indicating hostility or enmity
6. presaging ill fortune adv.
1. (`ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
2. unfavorably or with disapproval
3. with difficulty or inconvenience; scarcely or hardly
