This post really intrigued me.. I've never really thought about it; I know what curly hair looks like and what wavy hair looks like, but I'd never really put that much thought into it and that by using the words interchangeably would be at all offensive.
After doing some research (was intrigued on what the definition of curl was), I'd have to agree with tillymunchywaves...
all the definitions of curly I found said something like this..
adj. having curls, wavy (of hair); having a wavy grain (of wood)"
which could be where the confusion starts...
I also think that classes ones hair is a rather complicated as we are all so different, and our wave/curl patterns are unique.
I'd also have to agree with Del2c in terms of describing my hair.. i wouldn't say my hair has better waves.. I'd say it's "curling" more, it just makes more sense to me...?
I guess it will be interesting to see what others have to say about this, and whether this is a common occurrence.