Not to be that guy, but Merriam-Webster is pretty clear on the definition: `a sudden large change, development, or improvement`[1] http://www.merriam-webster.c

Not to be that guy, but Merriam-Webster is pretty clear on the definition: `a sudden large change, development, or improvement`[1] http://www.merriam-webster.com/dictionary/quantum%20leap http://www.merriam-webster.com/dictionary/quantum%20leap