This made me do my own investigating.  The `csh` manual in 2BSD said &quot;catenate&quot; earlier in &#x27;79.  Even before that, a comment in the ex (vi) 1.1 source code in 1BSD (1978) says &quot;catenate&quot;.<p>So it looks like Bill Joy made the mistake! (and the Bell Labs people thought it funny?)