An Etymological Dictionary of the German Language/Arbeit
Arbeit, f., ‘work, labour, employment,’ from MidHG. arbeit, arebeit, OHG. ar(a)beit, f., ‘labour, toil, distress.’ Corresponding to OSax. arƀêdi, n., ‘toil, hardship, suffering,’ arbêd, f., and Du. arbeid, m., AS. earfoð, earfeðe, n., ‘toil, hardship,’ earfeðe, adj., ‘difficult,’ Goth. arbaiþs(d), f., ‘oppression, distress’; OIc. erfiði, n., ‘toil,’ erfiðr, adj., ‘difficult, toilsome.’ Hence ‘toil’ must be accepted as the fundamental meaning of the cognates, and therefore any connection with the stem of Erbe is improbable. It has been compared with greater reason with OSlov. (Russ.) rabota, f., ‘servants' work,’ and rabŭ, robŭ, ‘servant, thrall,’ as prim. cognates, although this comparison is open to doubt. Lat. lâbor, ‘work,’ is at all events certainly not allied to it.