Grothendieck universe

Etymology
Named after (1928–2014), a German-born French mathematician.

Noun

 * 1)  A kind of universal set whose elements follow the rules of, and for which, with respect to an arbitrary set, an instance of its kind which has that set as a member may be posited to exist through an additional Tarski–Grothendieck axiom (which is not part of ZF but augments it, yielding Tarski–Grothendieck set theory).