Here's my question. Define "curvaceous" for me. Is that the "polite" way of saying fat, or just a way of saying "not bone thin"??
It depends on who's saying it -- or, more specifically, it usually depends on whether it's a man or a woman saying it.
Generally speaking -- and fellow guys, correct me if you disagree -- "curvaceous" to a man means something along the lines of, say, Kate Winslet or Nigella Lawson (those are just two examples that sprang to mind). Not rail thin, but a long way from anything you'd consider overweight. ("Rail thin" being someone, in my mind, who looks almost unhealthy -- Keira Knightley in some photos, for instance.) And if we're going to break it down even further, it generally means big breasts, slim waist, wide hips, and prominent ass.
When a woman says the word, however, it seems like it can mean any of a thousand things, all the way from "obese" to someone more along the lines of what I just described. There's really no way to tell -- and unfortunately, the word will continue to be bastardized the more obviously overweight women use it as a weasel word to avoid describing themselves as "fat. Same goes for curvy, rubenesque, meat on her bones, and so forth. The ones who annoy me the most, though, are those who claim to have a "womanly" shape, or who describe themselves as "real women," which I find incredibly arrogant, as if there's only one way a woman should look -- and that way is apparently overweight.
Oh, and a word about weight numbers -- as someone else noted, it's like men exaggerating their penis size in reverse; just as guys add two inches, women subtract 20 pounds. So men shouldn't be surprised when they discover the 130-pounder they've been dating actually weighs 150, nor should women be surprised that their boyfriend's eight-inch cock only reaches the six on the ruler.
My apologies for getting so wordy, but with the advent of online dating, this is a subject that affects a lot more people than I think we're aware of. It gets tedious having to pick your way through the minefield of intentionally vague descriptions and misleading photos out there.