High/lit. Over Cut
The Oberhau or High Cut in the 15th century context refers to any (long edge) cut from above.
Through reading of the text it seems that these cuts typically fall at an angle rather than straight down (by comparison a Scheitelhau falls more vertically) and are typically described as attacking specific opening to the left or right (for a right hander this is generally the upper right opening, as it seems the most natural cut to make for most people.
In Meyer's text this is written as the Oberhauw and is a more specific cut than the earlier tradition, with Meyer's cut which falling along a more strictly vertical line.
The closest cut in Meyer's system is the Zornhauw, which is a general diagonal long-edge cut, though the 15th century Zornhau by comparison, contains a range of tactical application information implicit to the technique, and the two should not be broadly conflated, despite the similarity of cut.