whip scorpion

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various arachnids of the order Pedipalpi, such as the vinegarroon, that resemble scorpions but have a slender whiplike process on the abdomen and no poisonous sting.

Century Dictionary and Cyclopedia

1. n. A false scorpion of the family Thelyphonidæ, having a long, slender abdomen like the lash of a whip, as Thelyphonus giganteus, of the southern United States: also there called grampus, mule-killer, and vinaigrier. The name is sometimes extended to the species of the related family Phrynidæ, and thus to the whole of the suborder Pedipalpi. See the technical names, and cut under Pedipalpi.

GNU Webster's 1913

1. n. (Zoöl.) any one of numerous species of arachnids belonging to Thelyphonus and allied genera. They somewhat resemble true scorpions, but have a long, slender bristle, or lashlike organ, at the end of the body, instead of a sting.

WordNet 3.0

1. n. nonvenomous arachnid that resembles a scorpion and that has a long thin tail without a stinger
2. n. nonvenomous arachnid that resembles a scorpion and that has a long thin tail without a stinger