When you have done your levelling work and you close your measuring polygon into the starting point, your measurements should show that the position of the starting point is the same as it was in the beginning of the polygon measurement, otherwise there is a closing error. (Actually, there always is, but it should not be to big.)

It seems like "accumulating error" were also used in English in the same meaning.

I couldn't find any good reference in the net, but this may do to some extent.

http://www.ssuet.edu.pk/newwebsite/civil.htm