fuzzball [TCP/IP hackers] n. A DEC LSI-11 running a particular suite of homebrewed software written by Dave Mills and assorted co-conspirators, used in the early 1980s for Internet protocol testbedding and experimentation. These were used as NSFnet backbone sites in its early 56KB-line days; a few are still active on the Internet as of early 1991, doing odd jobs such as network time service.