BIGGIN is a 6 letter word that starts with B.

1. \Big"gin\, n. [F. b['e]guin, prob. from the cap worn by
   the B['e]guines. Cf. {Beguine}, {Biggon}.]
   A child's cap; a hood, or something worn on the head.
   
         An old woman's biggin for a nightcap.    --Massinger.
   
   

2. \Big"gin\, n.
   A coffeepot with a strainer or perforated metallic vessel for
   holding the ground coffee, through which boiling water is
   poured; -- so called from Mr. Biggin, the inventor.
   
   

3. \Big"gin\, Bigging \Big"ging\, n. [OE. bigging. See
   {Big}, {Bigg}, v. t.]
   A building. [Obs.]