A while ago, Justine blogged about words she can never remember the name of. Talking about it with some friends, we discovered that nobody knows what 'erstwhile' means. Nobody. I certainly didn't. Some of the suggestions were:
All wrong. Read the definition here.
I remember getting all confused about 'caucasian' as a kid. I thought it meant 'asian'. It has 'asian' in it!
English. Wacky. Discuss.