Definition(s)
Spider
Device having retractable jaws or dogs used to support the riser on the uppermost connector support shoulder during running of the riser. NOTE The handling spider sits either on the rotary bushing or in the rotary table. It provides a hang-off point for the integral C/WO riser. Some spiders will lock to the rotary via the kelly drive pinholes in the master bushing. With the pins engaged, the spider can resist torque. For non-integral risers, tubing slips and false rotaries are used in lieu of the spider.
Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards
Spider
A device for the purpose of suspending tubular goods of any type from the drilling structure, not capable of being used as elevators, that have some element on the internal diameter to grip the outer diameter surface of the pipe body of various tubular goods, that are operated manually or by spring(s) and/or pneumatic or hydraulic power or other assist device or method.
Source:API SPECIFICATION 7K, Drilling and Well Servicing Equipment, Sixth Edition, December 2015. Global Standards