trithingEtymologyFrom Middle English trithing, tridinge, from Old English *þriðing, from Old Norse þriðjungr (“third part”).trithing means a riding (one of three ancient divisions of a county in England). Lexicurio rates it Sui generis — a strength score of 87 out of 100.nouna riding (one of three ancient divisions of a county in England)“Where a county is divided into three of these intermediate jurisdictions, they are called trithings, which were antiently governed by a trithing-reeve. These trithings still subsist in the large county of York, where by an easy corruption they are denominated ridings; the north, the east, and the west-riding.”