Proto-Indo-European root meaning "to be able, have power." It forms all or part of: dismay; deus ex machina; may (v.1) "am able;" might (n.) "bodily strength, power;" main; machine; mechanic; mechanism; mechano-; mage; magi; magic.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit mahan "great;" Greek mēkhanē "device, means," mekhos, makhos "means, instrument;" Old Church Slavonic mošti, Russian moč' "can, be able;" Old English mæg "I can," Gothic mag "can, is able," Old High German magan, Old Norse magn "power, might."