*tectonic*

{ } a. [ L. architectonicus, Gr. &unr_;. See Architect. ] 1. Pertaining to a master builder, or to architecture; evincing skill in designing or construction; constructive. “Architectonic wisdom.” Boyle. [ 1913 Webster ]

These architectonic functions which we had hitherto thought belonged. J. C. Shairp. [ 1913 Webster ]

2. Relating to the systemizing of knowledge. [ 1913 Webster ]

n. The science of architecture. [ 1913 Webster ]

n. (Geol.) A geological theory which holds that the crust of the earth (the lithosphere) is divided into a small number of large separate plates which float and move slowly around on the more plastic asthenosphere, breaking apart and moving away from each other at points where magma upwells from below, and, driven by such upwellings and other currents on the athenosphere, sliding past each other, colliding with each other, and in some cases being submerged (subducted) one below the other. This theory is now widely accepted, and explains many geological phenomena such as the clustered locations of earthquakes, mountain building, volcanism, and the similarities observed between the geology of continents, such as South America and Africa which are now far apart, but, according to the theory, were once joined together. The motions of such tectonic plates are very slow, typically only several centimeters per year, but over tens and hundreds of millions of years, cause very large changes in the relative positions of the continents. The consequence of such movement of plates is called continental drift. [ PJC ]

a. [ L. tectonicus, Gr. &unr_;, fr. &unr_;, &unr_;, a carpenter, builder. ] 1. Of or pertaining to building or construction; architectural. [ 1913 Webster ]

2. (Biol.) Structural. [ Webster 1913 Suppl. ]

3. (Geol. & Phys. Geog.) Of, pert. to, or designating, the rock structures and external forms resulting from the deformation of the earth's crust; as, tectonic arches or valleys; tectonic plates. [ Webster 1913 Suppl. +PJC ]