vt. 1. [MIT and Berkeley] To format code, especially LISP code, by indenting lines so that it looks pretty. This usage was associated with the MacLISP community and is now rare; prettyprint was and is the generic term for such operations.
2. [UNIX] To generate the formatted version of a document from the nroff, troff, TeX, or Scribe source. The BSD program 'vgrind(1)' grinds code for printing on a Versatec bitmapped printer.
3. To run seemingly interminably, esp. (but not necessarily) if performing some tedious and inherently useless task. Similar to crunch or grovel. Grinding has a connotation of using a lot of CPU time, but it is possible to grind a disk, network, etc.
See also hog.
4. To make the whole system slow.
"Troff really grinds a PDP-11."
5. 'grind grind' excl. Roughly, "Isn't the machine slow today!"