Can someone tell me an descriptive definition of budbreak. I can't find good definitions online.

This looks like a good definition.

http://www.google.com/search?hl=en&rlz=1G1GGLQ_ENUS308&defl=en&q=define:budbreak&sa=X&ei=jmm2TKeAGIKBlAfe69WQBg&ved=0CBQQkAE