The collective name of the orcs and goblins. Unless we have one already.
Originally referred to as the 'Elduergar', one of the words the provided the root of the common 'elemental', or 'Elduergar Midgar', 'Living Elemental'. Much evidence suggests, including the lore of several cultures, that the Duergar and the Sylvan are closely related, this includes similar terminology of their life cycles, which they have as many other dominate races have such as the Ogre. Although, only the Ogre go through a stark and obvious metamorphosis, while the Sylvan and Duergar more have names for vaguely defined stages.
The Sylvan call both their old and young 'Gnome', or at least those frozen in such a state, and do so for their size. The Duergar are the same in reasoning but they do not grow and shrink, they just grow and grow and grow. The Duergar Gnome stage lasts half as long as a normal humanoid lifetime and for some Duergar breeds that is their whole life time. The Duergar are called 'Living Elementals' because their is a breed for every element, physically and metaphysically interwoven into their bodies. The Elemental, unlike the Aetherial, is purely physical and such a Duergar's mind is divorced from the nature of his body and any stereotypes of personality to a breed is born from preconceptions of the nature of that element and not any exaggerated truth.
The Duergar Gnome for that half lifetime grows from a tiny infant to half the size of an average humanoid. At this point, their physical connection to an element is purely aesthetic and they are entirely flesh, but on the metaphysical they find that magic of their element comes easier to them and their Gifted are likelier then other races to be Elemental Movers as appropriate. The stage called Duergar Dwarf comes around mid-life and is supposed to be when their element begin to physically grow from their bodies, replacing their flesh. At this point they are old, hence the stereotype of the beard dwarf, and sterile, hence the stereotype of the grumpy dwarf. This stage tends to last for another half a life time at which point most Duergar die, hence the stereotype of the short dwarf as their growth often goes from half to equal size of an average humanoid.
The Duergar Giant is when the element overwhelm the flesh and the Duergar is more of a skin shell holding within it its element. This stage can last a life time, although a Duergar likely to die at any point in it, and usually they grow to twice the height of an average humanoid. The final stage is the Duergar Titan when flesh is gone and all that is left is a facsimile of a humanoid with elemental flesh, held together by undying will of the Duergar spirit. At this point, death is certain but its date is not, the titan will keep growing and keep living as long as they can keep it together and by this point they've been doing it for so long they can last several lifetimes or more. The death of a titan is heralded by them losing their humanoid shape but even then a stubborn Duergar can hold unto life even as amorphous blob, although hardly do so sane.
The Duergar Loci, Genius Loci
, are titans that lost their shape but refuse to die. These individuals are so remarkable as to be considered landmarks, literally. Their is Ottovin's Pyre, a Flame Duergar Loci who is now a forest fire who has burned for fifty years as he tries futilely to regain his shape, Mt. Jia a Stone Duergar, Lake Wakanani, Igel's Glacier, Zorm Forest, each name for the individual that compromises them.