| thrust [thrǝst] GEOLOGY Overriding movement of one crystal unit over another. MECHANICAL ENGINEERING The weight or pressure applied to a bit to make it cut. MECHANICS 1. The force exerted in any direction by a fluid jet or by a powered screw. 2. Force applied to an object to move it in a desired direction. MINING ENGINEERING 1. A crushing of coal pillars caused by excess weight of the superincumbent rocks, the floor being harder than the roof. 2. The ruins of the fallen roof, after pillars and stalls have been removed. |