An Etymological Dictionary of the German Language/Raub
Raub, m., ‘robbery, spoil,’ from the equiv. MidHG. roup (gen. roubes), m., OHG. roub, m.; comp. OSax. rôf in nôdrôf. ‘violent wresting,’ Du. roof, m., ‘robbery,’ AS. reáf, n., ‘robbery, booty,’ allied to AS. reófan, ‘to break, rend,’ OIc. rjúfa, str. vb., ‘to break, rend’ (espec. used of a breach of contract); these are further connected with Lat. rumpo (Aryan root rup); comp. the Sans. root lup, ‘to shatter.’ Hence Raub seems to mean lit. ‘breach of contract.’? —