Google search defines a startup as "a newly established business".

Dictionary.com says "a new business venture, or a new commercial or industrial project".

Merriam-Webster says "a fledgling business enterprise".

I don't mean to be difficult but it's annoying that some folks on HN insist that PG's definition of "startup" is the only possible one. It's a useful definition, but people who use it the non-PG way are not wrong either.