Though it sounds like some kind of obscure element from the period table, bronteum is actually related to music and theater. It is defined as:
A device used to create the sound of thunder in a musical or dramatic performance (also called a tonitruone). It is usually a large, thin sheet of metal that reverberates when shaken.
I've always liked things like this, odd objects that give us interesting sounds. It's kind of like those videos you can see sometimes where someone is creating the sound effects for a movie.
The beginning of the word is the key - Bront. We get all kinds of cool stuff from that, such as Brontosaurus (the thunder lizard whose scientific name is actually Apatosaurus), brontophobe (that common fear of thunderstorms), and Brontes (one of the Cyclopes in Greek mythology).
Any other interesting B words you can think of?