RUBBING FRICATIVES

The word fricative - an important term to understand in the field of linguistics - was first used in the English language to describe anything caused by friction. By the 1860s, it, in some early books on language theory, started to be used in reference to the consonant type where air is forced out of the mouth between two articulators. It comes from the Modern Latin fricativus, which is a conjugation of the verb fricare, meaning "to rub" (this is also where friction comes from, through French. Other words like traffic and dentrifice have it as a component). Fricare, in turn, is thought to be from the reconstructed Proto-Indo-European root breyh, also "rub". Use of the word friction peaked in the 1940s, while the peak of fricative was in the 1970s. Usage according to Google Trends looks pretty regular, however.