Blue on blue incident - new euphemism for "friendly fire", itself an old euphemism for killing your own or your allies' troops in the fog of war or stupidity. Interestingly the etmology is a hangover from the cold war days when the bad guys were reds and good guys were blues.

Brand Conscious babies - popular wisdom suggests that you can now start imprinting as early as six months, around when speech begins to develop.

Brandalism - the way that libraries, art galleries etc. now have their walls defaced with the logos of their corporate sponsors.

Brain dump - usually used as a synonym for brain storming. In fact a shockingly stupid word to use seriously because of the obvious scatological witticisms it invites about the contents of your head.