From Middle English ille (“evil; wicked”), from Old Norse illr (adj), illa (adverb), ilt (noun) (whence Icelandic illur, Norwegian ille, Danish ilde), from Proto-Germanic *ilhilaz, from Proto-Indo-European *h₁elk- (whence Latin ulcus (“sore”), Ancient Greek ἕλκος (hélkos, “wound, ulcer”), Sanskrit अर्शस् (árśas, “hemorrhoids”) (whence Hindi अर्श (arś)).
ill (comparative worse or iller or more ill, superlative worst or illest or most ill)
- (obsolete) Evil; wicked (of people). [13th-19th c.]
- (archaic) Morally reprehensible (of behaviour etc.); blameworthy. [from 13th c.]
- Indicative of unkind or malevolent intentions; harsh, cruel. [from 14th c.]
- Unpropitious, unkind, faulty, not up to reasonable standard.
- Unwell in terms of health or physical condition; sick. [from 15th c.]
- Having an urge to vomit. [from 20th c.]
- (hip-hop slang) Sublime, with the connotation of being so in a singularly creative way.
- (slang) Extremely bad (bad enough to make one ill). Generally used indirectly with to be.
- (dated) Unwise; not a good idea.
ill (comparative more ill, superlative most ill)
- Not well; imperfectly, badly; hardly.
ill (plural ills)
- (often pluralized) Trouble; distress; misfortune; adversity.
- Harm or injury.
- Evil; moral wrongfulness.
- A physical ailment; an illness.
- (US, slang) PCP, phencyclidine.