How about the most blatant redefinition -- from "a guy hacking trees with an axe"?
>HN as a community is the last place I would like to see wholeheartedly accepting casual things as hacking.
Well, Paul Graham might have been a great hacker (and Robert Morris!), but HN was built more around an entrepreneurial community (YC et al).
As such, a lot of people here don't do deep hacking stuff. They do simple web services (and sometimes, reading some articles they make it sound like they're doing rocket science). Even the most celebrated of them, Facebook, Instragram, Groupon or what have you, are dead simple stuff, CS wise. There might have been some difficulty in handling their scaling, but that too is hardly a hard problem. (Stuff like what Google and Orbitz do are another matter entirely).
So, seeing that HN has tons of introductory or trivial Node, Mongo and similar articles, why should you expect to see the "old meaning" of hacker here? It's not like it's Lambda the Ultimate.