Sentence:  He gave <WSD>back</WSD> the money.   He needs his money <WSD>back</WSD>.   He was on vacation, but now he's <WSD>back</WSD>.   The office fell into chaos when you left, but now order is <WSD>back</WSD>. 
Meaning of the word marked with <WSD> tags:  To or in a previous condition or place.