Old English brad "broad, flat, open, extended," from Proto-Germanic *braithaz (cf. Old Frisian bred, Old Norse breiðr, Dutch breed, German breit, Gothic brouþs), of unknown origin. Not found outside Germanic languages. No clear distinction in sense from wide. Related: Broadly. Broad-brim as a style of hat (1680s, broad-brimmed) in 18c.-19c. suggested "Quaker male" from their characteristic attire.
"woman," slang, 1911, perhaps suggestive of broad (adj.) hips, but it also might trace to American English abroadwife, word for a woman (often a slave) away from her husband. Earliest use of the slang word suggests immorality or coarse, low-class women. Because of this negative association, and the rise of women's athletics, the track and field broad jump was changed to the long jump c.1967.
[1910+; probably from the notion ''broad in the beam'']