any of various tropical or subtropical arachnids (esp. order Uropygi) resembling the scorpion but having a long, whiplike tail at the end of the abdomen and no sting
See whip scorpion in American Heritage Dictionary 4
noun
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.