Scottish Gaelic, Scots an aw

Wikipedia sez:

Originally Thurso was known by the Celtic name of tarvodubron meaning "bull water" or "bull river"; similarly was tarvedunum standing for "bull fort" and the name of the town name may have its roots there. Norse influence translated its name to Thjorsá, then altered it to Thorsá, based on the deity of and translating as (the place on) Thor's River.

The local name, Thursa, derives from the Norse, as does the modern Inbhir Theòrsa. means a river mouth, and is generally found as Inver in many anglicised names