[ il ]
/ ɪl /

adjective, worse, worst; ill·er, ill·est for 7.



Nearby words

  1. ilium,
  2. ilk,
  3. ilka,
  4. ilkeston,
  5. ilkley,
  6. ill at ease,
  7. ill fame,
  8. ill feeling,
  9. ill humor,
  10. ill humour


    ill at ease, socially uncomfortable; nervous: They were ill at ease because they didn't speak the language.

Origin of ill

1150–1200; Middle English ill(e) (noun and adj.) < Old Norse illr (adj.) ill, bad

Can be confusedill sick1 (see synonym study at the current entry)

Synonym study

1. Ill, sick mean being in bad health, not being well. Ill is the more formal word. In the U.S. the two words are used practically interchangeably except that sick is always used when the word modifies the following noun: He looks sick ( ill ); a sick person. In England, sick is not interchangeable with ill, but usually has the connotation of nauseous: She got sick and threw up. sick, however, is used before nouns just as in the U.S.: a sick man. 4. See bad1.

Grammar note

See well1.


Origin of ill.

(def 4) < Latin illustrissimus



[ ahyl ]
/ aɪl /

contraction of I will.
Can be confusedaisle I'll isle

Usage note Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ill

British Dictionary definitions for ill


/ (ɪl) /

adjective worse or worst



Word Origin for ill

C11 (in the sense: evil): from Old Norse illr bad


abbreviation for



/ (aɪl) /

contraction of

I will or I shall
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ill
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for ill


[ ĭl ]


Not healthy; sick.
Not normal, as a condition; unsound.


A disease or illness, especially of animals.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with ill


In addition to the idioms beginning with ill

  • ill at ease
  • ill wind that blows no one any good, it's an

, also see under

  • get sick
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.