O.E.
bolla "bowl," merged with M.Du.
bolle "round object," borrowed 13c., both from P.Gmc.
*bul-, from PIE
*bhel- "to blow, swell" (see
bole). Infl. in meaning by L.
bulla "bubble, ball," ult. from the same PIE root. Extended 1500 to "round seed pod of flax or cotton."
Boll weevil is 1895, Amer.Eng.