Wiktionary
n. (context computing English) The length of time that a central processing unit was busy processing instructions for a particular program, function or task
Wikipedia
CPU time (or process time) is the amount of time for which a central processing unit (CPU) was used for processing instructions of a computer program or operating system, as opposed to, for example, waiting for input/output (I/O) operations or entering low-power (idle) mode. The CPU time is measured in clock ticks or seconds. Often, it is useful to measure CPU time as a percentage of the CPU's capacity, which is called the CPU usage.
CPU time and CPU usage have two main uses. The first use is to quantify the overall busyness of the system. When the CPU usage is above 70%, the user may experience lag. Such high CPU usage indicates insufficient processing power. Either the CPU needs to be upgraded, or the user experience reduced, for example, by switching to lower resolution graphics or reducing animations.
The second use, with the advent of multi-tasking, is to quantify how the processor is shared between computer programs. High CPU usage by a single program may indicate that it is highly demanding of processing power or that it may malfunction; for example, it has entered an infinite loop. CPU time allows to measure how much processing power a single program requires, eliminating interference, such as time executed waiting for input or being suspended to allow other programs to run. In contrast, elapsed real time (or simply real time, or wall clock time) is the time taken from the start of a computer program until the end as measured by an ordinary clock. Elapsed real time includes I/O time and all other types of waits incurred by the program.
Usage examples of "cpu time".
No doubt it was one of the computer jocks in data processing, calling to complain about the enormous amount of CPU time her cladistic regression program was soaking up.
What's needed here is more historical research, not more CPU time.
I can stay cloaked without much effort, sipping a few milliseconds of CPU time here, a few there.
If my opponents devote CPU time to analyzing my taunts and formulating retorts, that increases my chances of winning.
Finally I sign up for several hours of CPU time on a supercomputer.
It's simply a matter of running the right simulations: of course, you need good software, and an awful lot of CPU time.
And you won't believe how much CPU time it took to figure that out!