Specific, definite, concrete Prefer the specific to the general, the definite to the vague, the concrete to the abstract. William Strunk Jr. & E.B. White, The Elements of Style examples
Caustic (optics) Caustics made by the surface of water. In optics, a caustic is the envelope of light rays reflected or refracted by a curved surface or object, or the projection of that envelope of rays on another surface. The caustic is a curve or surface to which each of the light rays is tangent, defining a boundary of an envelope of rays as a curve of concentrated light. Wikipedia en.wikipedia.org Architectural CausticsCaustic Engineering caustics