type-ahead definition operating system
The facility where the user can type more characters before the system has fully responded to those already typed. Type-ahead is common on most current systems. It allows the user to type without worrying that the computer may miss input because it is temporarily busy, e.g. reformating a page, checking spelling, or simply suffering from network latency. There is usually some limit to the amount of input the system can buffer, beyond which it __will__ lose input.
[Equivalent term for speech recognition