I found these definitions online, except for the last one which I made up. They all seem to fit our experience related to the MMP patents.

Definitions: Pacer

1) A horse trained to move at a (slow?) pace in races

2) Same as pacemaker (hmm)

3) The PACER service provides on-line access to U.S. Appellate, District, and Bankruptcy court records and documents nationwide. The PACER Service Center is the Federal Judiciary ...

4) A perpetual flow of legal documents supporting the never ending delay of litigation.