Final answer:
A pocket veto occurs when the president does not sign a passed bill within ten days of receiving it, and Congress adjourned.
Step-by-step explanation:
A veto that occurs when the president does not sign a passed bill within ten days of receiving it, and Congress adjourned is known as a pocket veto. According to the U.S. Constitution, if the president does not sign a bill within ten days and Congress adjourns during that period, the bill is automatically vetoed and does not become law. This type of veto is different from a regular veto, where the president explicitly rejects a bill by signing a veto message.