Time-out

1. When referring to data communications, time-out refers to a disconnect that occurs because no data is being communicated. This commonly occurs for users who use a modem to connect to the Internet. Many ISPs will set a time-out to occur if no data is being communicated after a set period of time. This is commonly performed to help keep phone lines available.  
2. A type of error that occurs when a program does not receive a response from the computer, another program, and/or another computer. Depending upon how the program is written, this type of error may cause the program to quit or an error message to be displayed.

Also see: Error, Time