What is "demiard"

A demiard is a traditional French measure of volume which, after the French revolution introduced new decimal systems, persisted in French-speaking areas of North America such as Quebec and Louisiana. It is a half of a chopine or a quarter of a pinte. It has been asserted that it was originally half of an ard, an otherwise unknown unit. The French pinte was, in Paris, 48 cubic inches (pouces du Roi) but, in North America, the terms became associated with Anglo-Saxon measures of a similar size (pinte≡ quart; chopine≡ pint; demiard≡½-pint).

In modern Canadian usage it is a unit equal to 0.284 litres.