curl: [14] Curl seems to have been borrowed from Middle Dutch krul ‘curly’, and indeed the original English forms of the word were crolle and crulle. The present-day form arose in the 15th century by a process known as metathesis, whereby the sounds r and u were transposed. The Middle Dutch word came from a Germanic *krusl-, source also of German kraus ‘curly’. Modern Dutch krul, meanwhile, has given English cruller ‘small cake of twisted shape’ [19]. => cruller[curl etymology, curl origin, 英语词源]