hold back vt. 阻碍；退缩；隐藏；克制；隐瞒。
词典中解释为“（常指因恐惧或不愿让事情变得更糟而）退缩，不做”。=to not do something, often because of fear or because you do not want to make a bad situation worse

【例句】
We could not hold ourselves back.
我们不能克制自己。

He held back, terrified of going into the dark room.
他退缩了，不敢进入黑暗的房间。