An Etymological Dictionary of the German Language/Annotated/Glück
Glück, neuter, ‘luck, fortune, success, happiness,’ from Middle High German gelücke (by syncope glücke), neuter, ‘luck, accident’; Old High German *gilucchi is wanting; a specifically German word which in the 14th century passed in the form into Scandinavian (Swed. lycka, Danish lykke), and as luck into English (from Dutch geluk, ‘fortune’). On account of its meaning its connection with locken is dubious.