IMHO only.
Spinner is small, muscular, and uniformly slender (sorry, a poochy stomach disqualifies for a spinner).
Athletic can be any size but must be HWP and reasonably fit.
Average is a normal girl, no significant musculature, can have a flaw (belly, mommy damage, thick thighs, chubby butt, droopy tits, etc.).
Amazon is taller than me and preferably HWP or Thick (see below).
Thick means athletic with a layer (think Ashley Graham).
Curvy is Thick without any muscle tone, but still has a semblance of hour glass shape (no dunlop disease).
BBW is anything bigger than Curvy.
Again, strictly my opinion.