From the month (Latin (mensis) aprilis, probably a derivative of aperire ‘to open’, as the month when buds open and flowers appear). It forms part of a series with May and June, all names taken from months associated with the spring, a time of new birth and growth, and may originally have been intended as an English version of the supposedly French name Avril.
English and Dutch: from the personal name (Greek Nikolaos, from nikān ‘to conquer’ + laos ‘people’). Forms with -ch- are due to hypercorrection (compare Anthony). The name in various vernacular forms was popular among Christians throughout Europe in the Middle Ages, largely as a result of the fame of a 4th-century Lycian bishop, about whom a large number of legends grew up, and who was venerated in the Orthodox Church as well as the Catholic. In English-speaking countries, this surname is also found as an Americanized form of various Greek surnames such as Papanikolaou ‘(son of) Nicholas the priest’ and patronymics such as Nikolopoulos.