信口开河的英文：
[Literal Meaning]
at will/mouth/speak
to talk at random

[解释]
随口乱说一气。

[Explanation]
to talk as one pleases, especially nonsense

[例子]
你不要信口开河，事实是什么就说什么。

[Example]
You should not talk at random but tell the truth.

[英文等价词]
to talk through one's hat
big mouth
run off at the mouth
shoot off one's face
shoot off one's mouth

To shoot one’s mouth off
信口开河

Alcohol can induce a loosening of the tongue.
酒精可使人信口开河。

So this is not just idle talk.
所以，这不是信口开河。

This is an article basting the spokesman for irresponsible statements.
这是一篇斥责该发言人信口开河的文章。

Talk lengthily or in a rambling and pointless way
冗长地或信口开河、无针对性地谈

I'm talking off hand, simply speaking my mind.
我这是信口开河， 随便谈谈脑子里想的东西。

I'm talking offhand, simply speaking my mind.
我这是信口开河，随便谈谈脑子里想的东西。

Let my nephew and Goldthred swagger about their wager as they list.
让我外甥和戈德斯雷德去信口开河地打赌，随他们的便吧。