> API is indeed the correct word to describe a set of functions from a library (built-in or not).
Uncorroborated by WP, note.
> If you disagree perhaps you should share your preferred term here?
Library functions.
Uncorroborated by WP, note.
> If you disagree perhaps you should share your preferred term here?
Library functions.
> The term API is often used to refer to web APIs, which allow communication between computers that are joined by the internet. There are also APIs for programming languages, software libraries, computer operating systems, and computer hardware.