- Proper noun. (computing) A family of third-generation programming languages (c.1964 on).
- Proper noun. (programming) A family of third-generation computer programming languages (c.1964 on).
- Noun. A necessary commodity, a staple requirement.
- Noun. An elementary building block, e.g. a fundamental piece of knowledge.
- Noun. (military) basic training.
- Adjective. necessary, essential for life or some process.
- Adjective. elementary, simple, fundamental, merely functional.
- Adjective. (chemistry) Of or pertaining to a base; antonym of acidic.