[1]

A native object is any object supplied by an ECMAScript implementation independent of the host environment. Standard native objects are defined in this specification. Some native objects are built-in; others may be constructed during the course of execution of an ECMAScript program.

ECMAScript Language Specification (HTML version) ( 版) http://bclary.com/2004/11/07/#a-4.3.6

関連

[2] ネイティブ・オブジェクトでないオブジェクトをホスト・オブジェクトといいます。