Larry Smith wrote on Thu, Nov 20, 2008 08:34 PM UTC:
I stand upon a point from which I can choose several directions to move. I choose one direction, this is the first or 'zig'. Then having taken that direction, I now choose another or 'zag'.
I think you are confusing the zigzag pattern(or repetitive series of zigzag steps) to the simple zigzag step.
Check out the second definition of the noun version of this word at this site:
http://en.wiktionary.org/wiki/zigzag
What about the concept of 'forked'? Which fulfils the French definition of zigzag.
Sharp has nothing to do with the degree of the angle but with abrupt shift involved. A non-sharp turn would actually become an arc, though it can be tight it may not be considered 'sharp'.
I love etymology. I can talk about it all day. ;-)