built-in

动词 build-in:

1. make something an integral part of something else
   同义词：build in

形容词 built-in:

1. existing as an essential constituent or characteristic
   同义词：constitutional, inbuilt, inherent, integral

built-in

adj.（形容词）
Constructed as part of a larger unit; not detachable:
嵌入的：作为一个大整体的一部分建造的；不可分的：
例句：
a built-in cabinet.
嵌入的橱柜

Forming a permanent or essential element or quality:
永久性，必要的：作为或永久的必需的因素或品质的：
例句：
a built-in escape clause.
必要性的免责条款

【引伸】
built.-in.
n.（名词）