select the text and right-click on it.  or select it and middle-click
'Look'.  there's also a very complex chord for it, which is described
in the acme(1) manual pages:


          For example, to search for literal text one may execute Look
          text with button 2 or instead point at text with button 1 in
          any window, release button 1, then execute Look, clicking
          button 1 while 2 is held down.

andrey

ps: right clicking on acme(1) will open the manual page for acme ;)