Here is the Wikipedia definition:
Widdershins (sometimes withershins, widershins or widderschynnes) is a term meaning to go counter-clockwise, to go anti-clockwise, or to go lefthandwise, or to walk around an object by always keeping it on the left. i.e. literally, it means to take a course opposite the apparent motion of the sun viewed from the Arctic Circle, (the centre of this imaginary clock is the ground the viewer stands upon).[1] The Oxford English Dictionary's entry cites the earliest uses of the word from 1513, where it was found in the phrase widdersyns start my hair, i.e. my hair stood on end.
The use of the word also means "in a direction opposite to the usual", and in a direction contrary to the apparent course of the sun. It is cognate with the German language widersinnig, i.e., "against" + "sense". The term "widdershins" was especially common in Lowland Scots.
