earlyyoudaoicibaDictYouDict[early 词源字典]
early: [OE] Broken down into its equivalent parts in modern English, early means ‘before-ly’. It was a compound formed from Old English ǣr (ancestor of modern English ere ‘before’) and the adverb ending -ly, modelled probably on the parallel Old Norse form árligr. Ere itself was actually originally a comparative form, which before it was used for ‘before’ meant ‘earlier’.

Old English ǣr came from prehistoric Germanic *airiz, the comparative form of *air ‘early’. Related forms in other Indo-European languages, such as Greek eri ‘in the morning’ and Avestan (the sacred form of Old Iranian) ayarə ‘day’, suggest that its underlying meaning is ‘early in the morning’.
=> ere[early etymology, early origin, 英语词源]
early (adv.)youdaoicibaDictYouDict
Old English ærlice "early," from ær "soon, ere" (see ere) + -lice, adverbial suffix (see -ly (2)). Compare Old Norse arliga "early." The adjective is Old English ærlic. The early bird of the proverb is from 1670s. Related: Earlier; earliest.