Road construction

The fifth entry is il conglomerato bituminoso, and the first of the two words is a trap for anyone reading it as English. « Conglomerate » is heard in Britain in two places: the business pages, where it is a company that has swallowed several unrelated ones, and a geology textbook, where it is a rock of rounded pebbles set in a natural cement. Italian never narrowed the word that way. Il conglomerato is the ordinary technical name for any material made of loose grains held together by a binder, and the adjective beside it names the binder: il conglomerato bituminoso is asphalt, because the glue is bitumen, and il conglomerato cementizio is concrete, because the glue is cement. That pair is worth carrying away, because it makes plain what English hides. « Concrete » and « asphalt » are unrelated words and sound like two unrelated substances, while the Italian names say openly that they are one idea twice over — stone plus a glue — and that the whole difference between a motorway surface and a bridge pier is which glue was chosen. The root is the one inside « agglomerate »: glomus, a ball of wound yarn.