Definition of "Ill" :
noun: an often persistent bodily disorder or disease; a cause for complaining
adjective: presaging ill fortune
adjective: resulting in suffering or adversity
adjective: indicating hostility or enmity
"You certainly did me an ill turn."
adjective: affected by an impairment of normal physical or mental function
"Ill from the monotony of his suffering."
adverb: (ill' is often used as a combining form) in a poor or improper or unsatisfactory manner; not well
"He was ill prepared."
adverb: with difficulty or inconvenience; scarcely or hardly
"We can ill afford to buy a new car just now."
adverb: unfavorably or with disapproval
"Tried not to speak ill of the dead."