Wiktionary
forthan
conj. 1 (context now chiefly dialectal Northern England English) For this reason; therefore. 2 (context now chiefly dialectal Northern England English) For the reason that; because.
Usage examples of "forthan".
Three levels down from the main walls were dozens of roomsbedchambers, a communal kitchen, common rooms, and so forthan area accessed by a double door painted white and bearing a carved emblem that appeared to represent a sheaf of plumes, this the source of the name given to those who dwelled within.