Dream symbols and meanings from Bs to Bz are described here.
Bug or tiny insects : These creatures in dreams are often associated with irritation and frustrations.
Bullock cart : If it is associated as a vehicle, it denotes being relatively primitive.  Vehicles symbolise body or vehicle of expression.
Butterfly in a dream is a symbol of transformation [...]

This page posts Dream Symbols and their respective meanings ranging from Bf to Br.
Bill, invoice, payment: Associated with effects and consequences from past actions.
Birth: Giving birth to a child may represent the start of a new stage of an undertaking or life.
Blood: can be symbolic of energy and life force. If one is dreaming [...]

Here are some Dream symbols starting with the letter B and their meanings. Please understand that these are only generic interpretation. Each individual person may have his or her own unique meanings to any particular symbols.
Babarian: Unrefined and animalistic aspect of oneself.
Bath, shower: Signifies cleansing that could be spiritual, mental or emotional in nature.
Baboon: Associated [...]