I guess I have a narrower definition of hacking, specifically that it is using technology in a way it wasn't intended. If you ask someone for their credentials and they give them to you, I don't see that as being "a hack," although I guess modern parlance would say the victim "was hacked."
"Hacking" is in everyday parlance not too far from "gaining unauthorised access to a technical system."
Social engineering is often a very efficient alternative to rainbow tables, wiretapping, buffer overruns and other technical exploits.
It's often the only or best way too. The more secure a place is the easier it is to get in. People become very trusting. Carry a clipbord and look like you know where you're going and you can walk damn near anywhere.