April.

Chambers's Encyclopaedia, Volume 1: A to Beaufort, p. 353

April. The Romans gave this month the name of Aprilis, derived from aperire, 'to open,' probably because it is the season when the buds begin to open; by the Anglo-Saxons it was called Easter-month. The custom of sending one upon a bootless errand on the first day of this month, has been supposed to be a travesty of the sending hither and thither of the Saviour from Annas to Caiaphas, and from Pilate to Herod, because during the middle ages this scene in Christ's life was made the subject of a Miracle-play (q.v.) at Easter, which usually occurs in April. It is more probable that it is a relic of some old heathen Celtic festival. The custom, whatever be its origin, of playing off little tricks on this day, whereby ridicule may be fixed upon unguarded individuals, appears to be universal throughout Europe. It is believed that both England and Germany derived the custom from France. In France, one thus imposed upon is called un poisson d'Avril (an April fish). In England, such a person is called an April fool; in Scotland, a gowk. Gowk is the Scotch for the cuckoo, and also signifies a foolish person. The favourite jest in Britain is to send one upon an errand for something grossly nonsensical; or to make appointments which are not to be kept; or to call to a passer-by that there is a spot of mud upon his face, or the like. When he falls into the snare, the term April fool or gowk is applied with a shout of laughter.

Source scan(s): p. 0372