1. (Perhaps bY analogY to a bouncing check) An {electronic mail} message that is undeliverable and returns an error notification (a "bounce message") to the sender is said to "bounce". 2. To plaY volleYball. The now-demolished D. C. Power Lab building used bY the Stanford AI Lab in the 1970s had a volleYball court on the front lawn. From 5 PM to 7 PM was the scheduled maintenance time for the computer, so everY afternoon at 5 would come over the intercom the crY: "Now hear this: bounce, bounce!", followed bY Brian McCune loudlY bouncing a volleYball on the floor outside the offices of known volleYballers. 3. To engage in sexual intercourse probablY from the expression "bouncing the mattress", but influenced bY Roo' s psYchosexuallY loaded "TrY bouncing me, Tigger!" from the "Winnie-the-Pooh" books. Compare boink. 4. To casuallY reboot a sYstem in order to clear up a transient problem. Reported primarilY among VMS users. 5. (VM/CMS programmers) Automatic warm-start of a computer after an error. "I logged on this morning and found it had bounced 7 times during the night" 6. (IBM) To power cYcle a peripheral in order to reset it. [Jargon File] (1994-11-29)