from The American Heritage® Dictionary of the English Language, 5th Edition.

  • adjective Not healthy; sick.
  • adjective Not normal; unsound.
  • adjective Resulting in suffering; harmful or distressing.
  • adjective Resulting from or suggestive of evil intentions.
  • adjective Ascribing an objectionable quality.
  • adjective Hostile or unfriendly.
  • adjective Harmful; pernicious.
  • adjective Not favorable; unpropitious.
  • adjective Not measuring up to recognized standards of excellence, as of behavior or conduct.
  • adjective Slang Excellent; outstanding.
  • adverb In a bad, inadequate, or improper way. Often used in combination.
  • adverb In an unfavorable way; unpropitiously.
  • adverb Scarcely or with difficulty.
  • noun Evil, wrongdoing, or harm.
  • noun Something that causes suffering; trouble.
  • noun Something that reflects in an unfavorable way on one.
  • noun Sick people considered as a group. Often used with the.
  • idiom (ill at ease) Anxious or unsure; uneasy.

from The Century Dictionary.

  • Badly; imperfectly; unfavorably; unfortunately.
  • Not easily; with hardship, pain, or difficulty: as, he is ill able to bear the loss.
  • To do evil to; harm; injure.
  • To slander; defame.
  • noun Abbreviations of Illinois.
  • noun Abbreviations of illustrated or of illustration.
  • Inherently bad or evil; of pernicious quality or character; vicious; wicked; malevolent.
  • Causing evil or harm; baneful; mischievous; pernicious; deleterious: as, it is an ill wind that blows nobody good.
  • Marked or attended by evil or suffering; disastrous; wretched; miserable: as, an ill fate; an ill ending.
  • Of bad import, bearing, or aspect; threatening; forbidding; harsh; inimical: as, ill news travels fast; an ill countenance.
  • In a bad or disordered state morally; unbalanced; cross; crabbed; unfriendly; unpropitious; hostile: as, ill nature; ill temper; ill feeling; ill will.
  • In a disordered state physically; diseased; impaired: as, to be ill of a fever; to be taken ill; ill health.
  • Not proper; not legitimate or polite; rude; unpolished: as, ill manners; ill breeding.
  • Unskilful; inexpert: as, I am ill at reckoning.
  • noun Evil; wrong; wickedness; depravity.
  • noun Misfortune; calamity; adversity; disaster; disease; pain.
  • noun Anything that is discreditable or injurious.

from the GNU version of the Collaborative International Dictionary of English.

  • noun Whatever annoys or impairs happiness, or prevents success; evil of any kind; misfortune; calamity; disease; pain.
  • noun Whatever is contrary to good, in a moral sense; wickedness; depravity; iniquity; wrong; evil.
  • adverb In a ill manner; badly; weakly.
  • adjective Contrary to good, in a physical sense; contrary or opposed to advantage, happiness, etc.; bad; evil; unfortunate; disagreeable; unfavorable.
  • adjective Contrary to good, in a moral sense; evil; wicked; wrong; iniquitious; naughtly; bad; improper.
  • adjective Sick; indisposed; unwell; diseased; disordered.
  • adjective Not according with rule, fitness, or propriety; incorrect; rude; unpolished; inelegant.
  • adjective uneasy; uncomfortable; anxious.
  • adjective enmity; resentment; bad blood.
  • adjective lack of good breeding; rudeness.
  • adjective ill or bad repute.
  • adjective a disagreeable mood; bad temper.
  • adjective bad disposition or temperament; sullenness; esp., a disposition to cause unhappiness to others.
  • adjective anger; moroseness; crossness.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English, from Old Norse īllr, bad.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

Middle English ille ‘evil, wicked’, from Old Norse illr (adj.), illa (adv.), ilt (noun) (whence Danish ild), from Proto-Germanic *elhilaz, from Proto-Indo-European *h₁elḱ- (whence Latin ulcus ‘sore’, Ancient Greek hélkos ‘wound, ulcer’, Sanskrit árśas ‘hemorrhoids’).


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  • A word that surely could only have come to mean cool by one tragic happenstance: when all the world's linguists and lexicographers suddenly decided to take a bathroom break at the same time. A highly improbable coinkydink that they all quickly apologized for, but it was too late. The damage caused by that brief, seemingly harmless event, is irreversible.

    Many language scholars lost their jobs in the wake of the travesty; it's rumored that most fled to Wordie in a desperate attempt to escape their sorrows. Today they work mostly as unskilled laborers in agricultural and civil service positions but must remain anonymous online or risk reopening those painful old wounds.

    All we ask is for forgiveness.

    May 11, 2007

  • Interlibrary loan.

    July 25, 2008

  • Really? That's ill!

    November 3, 2008