push the envelope

Definitions

Commerce

  • verb to go beyond normal limits, especially to attempt to do something that is highly innovative and rather risky

Slang

  • verb to test or extend limits, go too far. The term, used in fiction by Tom Wolfe and john Grisham, derives from the jargon of test pilots: the envelope is the ultimate technical capability as expressed on a graph.
http://www.dictionarycentral.com/definition/push-the-envelope.html