torfer

From Middle English torfer, torfere, torfayr, a borrowing from Old Norse torfǽra (“a difficult road or passage”) whence the Icelandic torfæra (“an obstacle; a difficult drive, a difficult route”) and torfær (“of a path: difficult to negotiate”), torfǽrr (“hard to pass”, adjective), from tor- (“hard, difficult”) + fara (“to go, pass”). More at tore, fare.

来源：wiktionary