An Etymological Dictionary of the German Language/Annotated/Mage

by Friedrich Kluge

Mage, masculine, formed from the equivalent Middle High German mâc (g), masculine, Old High German mâg, masculine, ‘kinsman’; corresponding to Old Saxon mâg, Anglo-Saxon mœ̂g, masculine, ‘kinsman.’ The allied terms in the East Teutonic languages denote special degrees of relationship; compare Gothic mégs, ‘daughter's husband,’ Old Icelandic mágr, ‘brother-in-law, son-in-law, father-in-law.’ Probably mâg signified originally ‘one who is related by marriage.’ High German distinguishes between Schwert- and Spillmagen, just as Middle High German does between swërtmâge, ‘relatives on the male side,’ and spinnelmâge, ‘relatives on the female side’; similarly in Anglo-Saxon spërmagas and spinelmâgas.