You know that it in fact means east too, right? Another word that means two things is åt, which can mean both ate and toward.
I'll tell you an old Swedish riddle that might help you remember that the word means both things:
Två män satt i en roddbåt. Den ena rodde åt väst och den andra åt ost. Åt vilket håll färdades båten och varför?
'Two men were sitting in a rowboat. One was rowing to the west and the other to the east [or: 'ate cheese']. In what direction did the boat travel and why?'
So the answer is that the boat traveled westwards, because only one of them was rowing, the other one was just eating cheese!