<networking, jargon> An absence, failure or inadequacy of flow control mechanisms causing the sender to overwhelm the receiver. The implication is that, like trying to drink from a firehose, the consequenses are worse than just loss of data, e.g. the receiver may crash.
Try this search on Wikipedia, OneLook, Google
Nearby terms: firebottle « firefighting « Firefox « firehose syndrome » firewall » firewall code » firewall machine