might (v.)

Old English mihte, meahte, originally the past tense of may (Old English magen "to be able"), thus "*may-ed." The noun might-have-been "something that might have happened but did not," also "someone that might have been greater but wasn't," is by 1848.

"quality of being able, ability to do or act, power," Middle English might, from Old English miht, earlier mæht "bodily strength, power; authority, dominion, control; ability," from Proto-Germanic *makhti- (source also of Old Norse mattr, Old Frisian, Middle Dutch, Dutch macht, Old High German maht, German Macht, Gothic mahts), a Germanic suffixed form of the PIE root *magh- "to be able, have power."