Tenacious Has Latin Roots

For the more than 400 years that tenacious has been a part of the English language, it has adhered closely to its Latin antecedent: tenax, an adjective meaning "tending to hold fast." Almost from the first, tenacious could suggest either literal adhesion or figurative stick-to-itiveness. Sandburs are tenacious, and so are athletes who don't let defeat get them down. We use tenacious of a good memory, too—one that has a better than average capacity to hold information. But you can also have too much of a good thing. The addition in Latin of the prefix per- ("thoroughly") to tenax led to the English word pertinacious, meaning "perversely persistent." You might use pertinacious for the likes of rumors and telemarketers, for example.