runtime
The environment and period during which a program is executing, as distinct from compile time or design time.
Full Definition
In developer tool documentation, 'runtime' appears both as a noun (the execution environment, e.g., 'Node.js runtime', 'Java runtime') and as an adjective modifier (e.g., 'runtime error', 'runtime dependency'). As a noun, it can refer to the software layer that manages program execution—handling memory, threading, and I/O—or simply to the phase when code is running. Editors must ensure consistency: 'runtime' is one word (not 'run time' or 'run-time') in modern technical usage, though legacy documents may use the hyphenated form. Distinguish from 'build time' and 'compile time', which refer to earlier phases in the software lifecycle.
Usage
Usage note: One word as both noun and adjective in modern usage. Flag 'run-time' and 'run time' as non-standard and update to 'runtime'.
In Context
- "A runtime error occurred because the array index exceeded its bounds." — Error message documentation
- "The application requires the .NET runtime to be installed on the target machine." — System requirements guide