1. airhead –stupid
My sister’s boyfriend is a real airhead. He even doesn’t know who Obama is.
2. crash – sleep in a convenient place
I need a place to crash. / You can crash here, though it’s not very comfortable.
3. all wet –completely wrong
Your ideas about politics are all wet. / If you think the house price will come down, you are all wet.
4. beat– exhausted
After working all day I am really beat.
5. boo-boo — mistake
If you make another boo-boo like that, you won’t have a job.
I made a boo-boo in my presentation — I hope no one notice it!