The following is a quote from Naming Infinity: A True Story of Religious Mysticism and Mathematical Creativity By Loren Graham, Jean-Michel Kantor
The students were so devoted to their teachers' studies of set theory that they made fun of mathematicians who worked in other areas, giving their topics comic titles such as "impartial differential equations," "theory of improbability," and "different finitenesses."
"impartial differential equations" is for partial differential equations, and "theory of improbability," is for theory of probability, but what's "different finitenesses"?