Where words and phrases come from is a fascinating subject, full of folklore and historical lessons. (Today, we begin with phrases beginning with I)

If the shoe (or cap) fits wear i- (If a description applies to you, then accept it.)

Origin - This phrase has been around since at least the early 18th Century, and is probably older. The expression is the American version of the earlier British phrase 'If the cap fits, wear it', which is also still in general use. Daniel Defoe used the earlier phrase in the satirical poem The Dyet of Poland. Defoe had the work printed in London in 1705. The change from cap to shoe may well have been influenced by the Cinderella story, which has a snug-fitting slipper as the primary plot device. Versions of the tale that include the 'lost slipper' scenario were well known in the USA and Europe by 1773.

Ill-gotten gains - (money gained by questionable means)

Origin - This is all that is left in general use of a proverb that ran 'Ill-gotten gains never prosper'. This first appeared in English in 1519 in the form 'Evil gotten riches will never prove long', and Shakespeare has it in the form 'Didst thou never hear / That things ill got had ever bad success (Henry VI, part 3, II.ii). Ill-gotten gains had become separated from their proverb by the late 17th Century, and were a cliché by the 19th.

In a nutshell - (concisely expressed)

Origin - A nutshell is small enough to be a symbol for anything brief. There is no need for further explanation, though there are curious stories of attempts to copy substantial documents, such as the entire Bible, in letters so small that the resultant document will literally fit in a nutshell. Roman literature has a reference to the writing out of the whole of Homer's Iliad (17,000 lines) in this way.

In clink - (in prison)

Origin - The Clink was a prison in London dating from the 12th Century, when it formed part of the Bishop of Winchester's palace and was used to house offenders against ecclesiastical codes. It was burned down in 1780 by the Gordon rioters. During its varied history, it was also a debtors' prison. Its name seems to come from a Middle English word which has also given us 'clinch' and 'clench': the underlying sense is that of secure fastening. The word passed from being the name of one particular prison to being a general name for any prison, though it is now rather dated slang.

In cold blood - (ruthlessly, without excitement, not in a passion)

Origin - A relic of early medical theory: becoming hot with excitement or exertion was supposed to be the result of blood getting hot. The same idea persists in make one's blood boil (make angry). By the same token, something done with deliberation, without the heat of passion, was supposed to be a product of cold blood.

In fine fettle - (in good order or condition)

Origin - Fettle is an old word meaning condition, order or shape. Nowadays, it rarely appears on its own. In the past we might have heard 'good fettle' or bad fettle', and in John Barleycorn by Jack London, published in 1913: 'Those fifty-one days of fine sailing and intense sobriety had put me in splendid fettle.' The origin of the word fettle is somewhat obscure. It probably comes from the Old English fetel for a belt, so fettle first meant to gird oneself up, as for a heavy task.