What is a failed startup? How do you define it?

I was watching people tweet from the Pipeline Fund Conference. Looks like a great event. Here is one of my favorite tweets:

@PipelineFund failure another step in your experience ladder, NOT scarlet letter, as #entrepreneurs we’ve ALL had failures #PFFConf

But the fundamental question remains: when do you fail?

At a recent HackersFounders event, I met a hacker/founder and eventually talked about the meaning of a failed startup. I told him about my failure (4 months of research, surveys, prototyping, and eventually death by IRS regulations). According to said hacker/founder, this was not a failure because I never “started.” He considered my work a “side project,” which never rose to the level of a startup.

Which brings us to another question: how do you define a startup? That hacker/founder claims that a startup is a company that has taken funding or is earning revenue.

So the last four months did not lead to a scarlet letter. Apparently I was not working on an actual “startup” or, if I was, the failure is more of a merit badge than a scarlet letter. Bottom line, however, is that my “side project” is dead. And that sucks — not because it “failed,” but because I’m not waking up with the rush of working on something big and meaningful.