The Collaborative International Dictionary
Cucking stool \Cuck"ing stool`\ (k?k"?ng st??l`). [Cf. AS.
scealfingst[=o]l, a word of similar meaning, allied to
scealfor a diver, mergus avis; or possibly from F. coquine a
hussy, slut, jade, f. of coquin, OE. cokin, a rascal; or cf.
Icel. k?ka to dung, k?kr dung, the name being given as to a
disgracing or infamous punishment.]
A kind of chair formerly used for punishing scolds, and also
dishonest tradesmen, by fastening them in it, usually in
front of their doors, to be pelted and hooted at by the mob,
but sometimes to be taken to the water and ducked; -- called
also a castigatory, a tumbrel, and a trebuchet; and
often, but not so correctly, a ducking stool.
--Sir. W.
Scott.
Douglas Harper's Etymology Dictionary
early 13c., from cuck "to void excrement," from Old Norse kuka "feces" (the chair was sometimes in the form of a close-stool). Also known as trebucket and castigatory, it was used on disorderly women and fraudulent tradesmen, either in the form of public exposure to ridicule or for ducking in a pond.
Wiktionary
n. A kind of chair formerly used for punishing scolds and dishonest tradesman, by fastening them in it, usually in front of their doors, to be pelted and hooted at by the mob, but sometimes to be taken to the water and ducked.
WordNet
n. an instrument of punishment consisting of a chair in which offenders were ducked in water [syn: ducking stool]
Wikipedia
Cucking stools or ducking stools were chairs formerly used for punishment of disorderly women, scolds, and dishonest tradesmen in England, Scotland, and elsewhere. The cucking-stool was a form of wyuen pine ("women's punishment") as referred to in Langland's Piers Plowman (1378). They were both instruments of public humiliation and censure primarily for the offense of scolding or back biting and less often for sexual offenses like bearing an illegitimate child or prostitution.
The stools were technical devices which formed part of the wider method of law enforcement through social humiliation. A common alternative was a court order to recite one’s crimes or sins after Mass or in the market place on market day or informal action such as a Skimmington ride.
They were usually of local manufacture with no standard design. Most were simply chairs into which the offender could be tied and exposed at her door or the site of her offence. Some were on wheels like a tumbrel that could be dragged around the parish. Some were put on poles so that they could be plunged into water, hence "ducking" stool. Stocks or pillories were similarly used for punishment of men or women by humiliation.
The term "cucking-stool" is older, with written records dating back to the 13th and 14th centuries. Written records for the name "ducking stool" appear from 1597, and a statement in 1769 relates that "ducking-stool" is a corruption of the term "cucking-stool". Whereas a cucking-stool could be and was used for humiliation with or without ducking the person in water, the name "ducking-stool" came to be used more specifically for those cucking-stools on an oscillating plank which were used to duck the person into water.