To delay or obstruct.
I expect it will set us back by a day or so, but I think a side trip will be worthwhile.
To remove from or allow distance.
Set it back from the road by twenty or thirty feet.
To install or position behind a boundary or surface, or in a recess.
The statue was set back in a niche.
To cost money, as.
How much do you suppose that fancy dress set her back?