出典:Wiktionary
Metathetic variant of olr, itself a variant of alr, itself a contraction of aller, itself a form of alder closer to the original 古期英語 form of alor, aler (the d was a phonetic addition in Middle English); compare the English oryelle, as well as the Old High German erila, the Middle High German erle, and the Modern German Erle.
Pronunciation spelling.