Know why cattywampus was trending last week?
To uncerimoniously disconnect someone from a system without prior warning. BBS Sysops routinely "borf" pest users by turning off the modem or by hitting the "auto-borf" key sequence.
You can also be "borfed" by software dropping carrier due to a bug.
The origin of the term is unknown but it has been in use since at least 1982.