Meaning

adverb powerfully or vigorously

adverb (Southern regional intensive) very; to a great degree

originFrom Middle English mightili (“with might, powerfully, strongly; forcefully, violently; greatly; etc.”), from Old English meahtiglice (“with might, powerfully, mightily”), from meahtiġ, mihtiġ (“powerful, mighty”) + -līċe (suffix forming adverbs). Mihtiġ is derived from Proto-Germanic *mahtīgaz (“mighty”), from *mahtiz (“force, strength; ability, power”) (ultimately from Proto-Indo-European…

Etymology from Wiktionary, CC BY-SA 3.0