Well we all know about abbreviations can't from can not, and didn't from did not. I was curious, what does won't stand for, because I had my spell chacker put an apostrophe in it, and I can't think for the life of me what it would stand for, "woe not" is the only thing that comes directly to mind, and it doesn't really make sense. Can anybody help?

Don't (there you are - contraction used straightaway)why it should be spelt and pronounced as it is. Someone out there may be able to give precise reasons. Maybe that present day 'will not' was pronounced differently originally -Middle English / Old English and sounded more like 'wol not, than the narrow 'i' sound of will. You can see and hear why it might have sounded like 'won't - spelt like 'woln't' and became 'won't'. At least that's a theory. Probably totally wrong!

The contraction won't for will not was first recorded in Middle English (before 1475) as wynnot, later (1584) wonnot (compare cannot and can't), the form won't being first recorded in 1667 in Pepys' Diary.

Chambers Dictionary of Etymology.

Thanks. Now it makes a lot more sense.

I always thought the word "spelt" was a mistake, but I saw it here so many times, I looked it up.
Besides being a kind of agricultural crop, (wheat, I think) Webster's says:
spelt: A chiefly British past and past participle of "spell." I learned something-imagine!