(as) honest as the day is long
意为“信守诺言的”，同义表达有as good as (one’s) word。

Tom is as honest as the day is long – if he promised to help you move, then he’ll be here.
汤姆言出必行——如果他答应帮你搬家，他就一定会来的。

an honest mistake
意为“无心之失”。

It was an honest mistake! How was I to know that you wouldn’t want me to send that letter with the rest of the mail?
这是无心之过！我怎么知道你不想让我把那封信和其他邮件一起寄出去？

earn an honest penny
意为“以正当手段谋生”。

I’m just an ordinary businessman, trying to earn an honest penny.
我只是个普通生意人，想老老实实赚点钱谋生。

honest!
用于强调说的是事实。

I swear it wasn’t me who broke the lamp, honest!
我发誓不是我打破了灯，真的！


if I’m honest
意为“说句实话，说句心里话”。

– So how do you feel about this plan?
– Well, if I’m honest, I think it’s a big mistake.
— 你觉得这个计划怎么样？
— 嗯，说心里话，我认为这是一个大错误。