1560s, "wolf spider," (Lycos tarantula), from Medieval Latin tarantula, from Italian tarantola, from Taranto "Taranto," seaport city in southern Italy in the region where the spiders are frequently found, from Latin Tarentum, from Greek Taras (genitive Tarantos; perhaps from Illyrian darandos "oak"). Its bite is only slightly poisonous. Popularly applied to other great hairy spiders, especially the genus Mygale, native to the warmer regions of the Americas (first so called in 1794).
tarantula ta·ran·tu·la (tə-rān'chə-lə)
n. pl. ta·ran·tu·las or ta·ran·tu·lae (-lē')
Any of various large, hairy, chiefly tropical spiders of the family Theraphosidae, capable of inflicting a painful but not seriously poisonous bite.