The Collaborative International Dictionary
Mygale \Myg"a*le\, prop. n. [L., a field mouse, Gr. ?.] (Zo["o]l.) A genus of very large hairy spiders of the family Ctenizidae, having four lungs and only four spinnerets. They do not spin webs, but usually construct tubes in the earth, which are often furnished with a trapdoor. The South American bird spider ( Mygale avicularia), and the crab spider, or matoutou ( Mygale cancerides) are among the largest species. They are also called trapdoor spiders. Some of the species are erroneously called tarantulas, as the Texas tarantula ( Mygale Hentzii).
Tarantula \Ta*ran"tu*la\, n.; pl. E. Tarantulas, L. Tarantul[ae]. [NL., fr. It. tarantola, fr. L. Tarentum, now Taranto, in the south of Italy.] (Zo["o]l.) Any one of several species of large spiders, popularly supposed to be very venomous, especially the European species ( Tarantula apuli[ae]). The tarantulas of Texas and adjacent countries are large species of Mygale. [Written also tarentula.]
Tarantula killer, a very large wasp ( Pompilus formosus), which captures the Texan tarantula ( Mygale Hentzii) and places it in its nest as food for its young, after paralyzing it by a sting.