Of relatively recent origin and uncertain etymology. It is first recorded in the 19th century. It may be a shortened form of Belinda, an adoption of Spanish linda ‘pretty’, or a Latinate derivative of any of various other Germanic female names ending in -lind meaning ‘weak, tender, soft’. It was popular in the 20th century, especially in the 1950s.
English and Scottish: patronymic from the medieval personal name Nel or Neal, Anglo-Scandinavian forms of the Gaelic name Niall (see Neill). This was adopted by the Scandinavians in the form Njal and was introduced into northern England and East Anglia by them, rather than being taken directly from Gaelic.