hinge

n. 铰链,关键,枢纽
v. 装铰链,靠铰链移动,依...而移

The door opens easily because the hinges were oiled.

这门开起来很容易，因为合页上了油。

A casement is a window that opened by means of hinge at the side.

竖铰链窗是一种用边上的铰链开启的窗户。