2229: clog Jan 21, 2021

A clog today refers to any sort of block, and much like with ‘block’ itself, its origins are essentially wooden. Although the precise root of ‘clog’ is unknown, it used to denote a mass of wood, related to the word ‘log’ and Norwegian ‘klugu’ (knotted wood). The word, once also used to denote large jewelry or testes only retains any connection to wood in the case of the shoes, clogs.

2225: block Jan 17, 2021

The original sense for a block was that of a large, solid piece of wood. This was only generalized in the late Middle Ages to mean 'any solid piece', originally with the senses of an executioner's block, and then later a stump from which to sell slaves. Other Germanic languages have related words connoting trees or large planks of wood, but the English block eventually related to anything solid, usually prismatic etc. to the point as a verb (or as a noun in 'blockade') it came to mean 'prevented from moving'. This is also related to bloc, which in Old French simply meant 'log', but now in English means a solid group, especially referring to political entities.