run time 1. The elapsed time to perform a computation on a particular computer.
2. The amount of time a processor actually spent on a particular process and not on other processes or overhead (see time-sharing). 3. The period of time during which a program is being executed, as opposed to compile-time or load time. The term should be hyphenated when used as an adjective. 4. run-time support. Last updated: 2001-09-14