"ill" 是一个 多义词，根据上下文的不同，它可以作为以下词性：
形容词
生病的：He was very ill.
坏的：an ill-intentioned person
邪恶的：an ill deed
不吉利的：an ill-fated day
副词
不利地：He spoke ill of sb.
恶劣地：The weather is ill today.
几乎不：I am almost ill.
名词
疾病：He has been suffering from an illness.
不幸：An ill fate befell him.
坏话：He spoke ill of his rival.
综上所述，"ill" 可以作为形容词、副词和名词使用，具体词性需要根据句子的语境来判断。