A well known reference, Eric Raymond's "jargon file" a.k.a. "hacker's dictionary" offers 9 definitions, much broader and seemingly older than keypress timings:

A well known reference, Eric Raymond's "jargon file" a.k.a. "hacker's dictionary" offers 9 definitions, much broader and seemingly older than keypress timings: http://catb.org/~esr/jargon/html/H/hack.html http://catb.org/~esr/jargon/html/H/hack.html ( see also http://catb.org/~esr/jargon/html/index.html http://catb.org/~esr/jargon/html/index.html and https://en.wikipedia.org/wiki/Jargon_File https://en.wikipedia.org/wiki/Jargon_File )