Noun
A whip spider or vinegaroon, any spider of order Uropygi (now often Thelyphonida)
Certain spiders in order Araneae
Platyoides and other genera of family Trochanteriidae, of Africa, which can fold their fourth pair of legs over their back like a scorpion.
Arachnura in the family Araneidae (scorpion-tailed spiders)
Source: en.wiktionary.org