pig out (on something)
狼吞虎咽地大吃
I love to pig out on ice cream.
我疯狂爱吃冰激凌。
The food was free, so I pigged out.
那里吃的不要钱，所以我吃了好多。

when pigs fly
绝对不可能
Sure he'll pay for the drinks-when pigs fly.
他才不会给我们买喝的！

put lipstick on a pig
粉饰某物来诱导或欺骗别人。
It looks like they've just put lipstick on a pig for the iPhone SE. It's just the same phone as 2 years ago, but in bright new colors.
苹果公司只是粉饰了一下iPhone SE，这手机和之前那款明明就差不多，只不过颜色不一样啊。

cast-iron stomach
铁胃
Jack has such a cast-iron stomach that he can eat a ghost pepper and feel perfectly fine afterward.
强子的胃真的好，他吃超辣的辣椒都完全没反应！（假的，强子不是很能吃辣嘻嘻）
You must have a cast-iron stomach if you're having apples and coffee for breakfast!
如果你早餐一边吃苹果一边喝咖啡还觉得OK的话，你一定有一个铁打的胃！

everything but the kitchen sink
一个人能想到的所有东西
John orders everything but the kitchen sink when he goes out to dinner, especially if someone else is paying for it.
John每次去餐厅吃饭都会把菜单上的点完，尤其是有人买单的时候。
Morning English podcasts could include topics about everything…. possibly even the kitchen sink!
我们早安的节目有你们能想象到的各种各样的主题哦！hin有趣的咧！

put a sock in it
往某人的嘴里塞袜子，就是表示要别人闭嘴。（是一个比较不礼貌的用法哦，不要对长辈对同事说）
Put a sock in it, all of you. I'm trying to watch TV.
诶诶诶你们都给我闭嘴！我要看我爱豆了！
Oh, put a sock in it! No one wants to hear your complaints anymore.
我的天哪你可闭嘴吧！没人想听你抱怨了OK？