Replicator: A system able to build copies of itself when provided with raw materials and energy. [FS]
Rheology: the study of the deformation and flow of matter under the influence of an applied stress, which might be, for example, a shear stress or extensional stress. The experimental characterisation of a material's rheological behaviour is known as rheometry, although the term rheology is frequently used synonymously with rheometry, particularly by experimentalists. Theoretical aspects of rheology are the relation of the flow/deformation behaviour of material and its internal structure (e.g. the orientation and elongation of polymer molecules), and the flow/deformation behaviour of materials that cannot be described by classical fluid mechanics or elasticity. This is also often called Non-Newtonian fluid mechanics in the case of fluids.