What does /usr mean?

[TVR%CCRMA-F4 at SAIL.Stanford.EDU]

A dozen or so years ago, i always thought that /usr was where users and a
few other things lived.  Those were the days of single platter disks, and
you were lucky to have two of them.  Sources filled most of one, and much
of what was left over was gobbled by things like /bin, etc. The other was
used mostly for users. The machine in question required more space than a
typical system at the time, since it was an early network UNIX and also a
speech system (requiring lots of sound files).  Of course, these are just
recollections from the dim, dark past, and someone who has hacked on UNIX
more continuously may remember better than i do.
							-- Tovar