ham sandwich theorem

Etymology
By analogy with cutting a sandwich having three layers (two of bread and one of ham), for the case where n=3.

Proper noun

 * 1)  A theorem stating that, given n measurable "objects" in n-dimensional Euclidean space, it is possible to divide all of them in half (with respect to their measure, i.e. volume) with a single (n−1)-dimensional hyperplane.