in a left-handed or contrary direction; counterclockwise
"And the waves beat upon the one hand, and upon the other the dead leaves ran; and the clouds raced in the sky, and the gulls flew widdershins." — Robert Louis Stevenson, The Song of the Morrow, 1896
About the Word:
English speakers got widdershins from an old German word meaning "to go against," and by the mid-1500s we were using the word as we use it today – as a synonym for counterclockwise.
For the first 200 years of the word's life, however, it had another meaning as well – it was used to describe that particular kind of bad hair day when unruly hair stands on end or simply falls the wrong way.