ill [ME] Ill is from Old Norse illr ‘evil’, and the commonest modern sense, ‘suffering from an illness or feeling unwell’, developed in the later medieval period. Before then a person would be *sick, as they still are in the USA. The idea of harm and evil is prominent in many English proverbs, such as it’s an ill wind that blows nobody any good [M16th]. This refers to the days of sailing ships. The wind might be blowing in the wrong direction for you, but it was sure to be blowing the right way for someone, somewhere—it would be a very bad or ‘ill’ wind that was of no help to anyone.