Middle English word myghtely comes from Old English miht (Power, ability. Strength, power.), Old English -līċe

Detailed word origin of myghtely

Dictionary entry	Language	Definition
miht	Old English (ang)	Power, ability. Strength, power.
-līċe	Old English (ang)
mihtlīċe	Old English (ang)
mihtlice	Old English (ang)	Mightily, powerfully, in power; with might.
myȝtly	Middle English (enm)

Words with the same origin as myghtely