An Etymological Dictionary of the German Language/Annotated/Öl
Öl, neuter, from the equivalent Middle High German öle, öl, neuter (with the variants ole, ol, and olei), Old High German olei, oli, neuter, ‘oil’; corresponding to Old Saxon olig; Dutch olie, Anglo-Saxon ele, neuter, ‘oil.’ Latin oleum, ‘oil,’ passed into High German before the 8th. century. Gothic adopted the term probably even half a century earlier from the Latin, the only assumption that can explain the remarkable Gothic form alêw. The approximate source of English oil, Middle English oile, is Old French oil, which with its Romance cognates. (Modern French huile) are also based on Latin oleum.