It's alteration of an established system with self-beneficial results in mind. It's a hack.
Each time we write a piece of software, we are taking an existing system (a computer), and altering it to perform a somewhat different task. Hack.
Each time I optimize a DSP system to take 10% less resources, its a hack.
Just stick 100 or 200 of these together, and we have moore's law.
My wife had epidurals during the delivery of our children. That, even though it was a medical procedure, was totally a hack :) Inserting novacaine into the spinal column to deaden nerve receptors == hacking the body :)
That doesn't mean it wasn't serious business or a big deal. It just means that we figured out a neat way to manipulate an existing system for beneficial results.