Final answer:
The lower molars with additional cusps in hominoids that aid in grinding food don't have a distinct name; they are generally known as molars.
Step-by-step explanation:
The lower molars of hominoids that have additional cusps for more surface space to grind food are known simply as molars, which are designed for crushing and grinding. In biological terminology, there is not a specific name given solely to lower molars with additional cusps; they are part of the general molar category. However, when discussing the evolution of hominids, one might refer to the molars of robust australopithecines, which had larger molars and jaws adapted for grinding tough plant material. Additionally, it's worth noting that these robust molars are sometimes recognized for their specific attributes pertinent to archaic hominin species.