Whoops, your body screwed up, and now you're XXY/XO/XXX, or XY, but your body doesn't care about the boysubstance, and developed female parts instead. Or you're born with no vagina, uterus, or ovaries at all.

Constructing a definition of "woman" is about as useful as trying to construct a definition of "human". You can approximate, but you'll never have a perfect image. (Diogenes, holding up a kitten: "Behold, a woman!")

Never mind that what's considered womanhood changes all the time. Should a woman be a fragile waif will fall ill and die at the slightest whisper of bad news, or a fierce fighter who strikes fear (and bullets) into the hearts of others? Depending on when, and who you ask the question, the answer will always differ.

Could you imagine proposing a woman be dressed in pink in the 1930s? Why, such a masculine colour will cause her uterus, and shortly after, her heart, to crumble into fine powder.