olemus
keskkonna vahenditega (programmikeelega, teekidega) määratud
(andmetüüp, funktsioon, muutuja vm)
= pertaining to a data type, function, variable, etc. that is determined by means of the environment (programming language, libraries)

näiteid
https://www.quora.com/What-is-the-difference-between-predefined-and-user-defined-data-type

https://cse.engineering.nyu.edu/~mleung/CS1114/s09/ch04/predefined_fcn.htm

http://desarrolloweb.dlsi.ua.es/cursos/2012/web-programming-with-php/predefined-variables

https://www.php.net/manual/en/reserved.variables.php