If you are bushed, you are very, very tired. It is informal and spoken: I’m bushed after that hike. You will hear it a lot in Australia and New Zealand, and also in North America; it is less common in British English, where worn out or exhausted do more of the work. It comes from bush, meaning wild country. The old picture is that you have been out in the wild all day, so you have nothing left — though people now say it after an exam, a long shift, or a night of studying, with no bushes anywhere. It is not a rude word, just relaxed. Though actually, in some places bushed can also mean lost in the bush, which is a different kind of trouble; the “very tired” meaning is the one you will meet first. It is an adjective here, not the past of a verb you can freely use as I bush, you bush.

累壞了、累翻了（口語）