mighty (adj.)youdaoicibaDictYouDict[mighty 词源字典]
Old English mihtig, earlier mæhtig, from miht (see might (n.)). Similar formation in Old Frisian mechtig, Old Saxon mahtig, Dutch machtig, German mächtig. As an adverb, it is attested from c. 1300, though now considered colloquial.[mighty etymology, mighty origin, 英语词源]