What is the origin of the term "broad" when it refers to a woman?

Refer to post 101744:

http://www.funtrivia.com/askft/Question101744.html

This source says that "broad" may be suggestive of broad hips or may refer to "abroadwife" for a woman away from her husband.

"O.E. brad, from P.Gmc. *braithaz (cf. O.Fris. bred, O.N. breiðr, Du. breed, Ger. breit, Goth. brouþs), of unknown origin. Not found outside Gmc. languages. Slang extension to meaning "woman" (1911) may be suggestive of broad hips, but it also may trace to Amer.Eng. abroadwife, for a woman away from her husband, often a slave. Earliest use suggests immorality or coarse, low-class women."

http://dictionary.reference.com/browse/broad

Broad is simply a slang term for woman. But more specifically refers to either a prostitute or a woman of loose morals.
http://wiki.answers.com/Q/What_does_the_word_broad_mean_when_used_to_talk_about_a_woman

In "Guys and Dolls" (1932), one character says "He refers to Miss Perry as a broad, meaning no harm whatever, for this is the way many of the boys speak of the dolls." This use was never really approved of, and the women's movement drove in the final coffin nails, so that it's rare to find a use of broad after 1975 that simply means 'woman'

http://www.randomhouse.com/wotd/index.pperl?date=20000612