spider (n.) Look up spider at Dictionary.com
late 14c., spydyr, from earlier spiþre, spiþur, spiþer (14c.), from Old English spiðra, from Proto-Germanic *spin-thron- (cognate with Danish spinder), literally "the spinner," from *spen-wo- "to spin" (see spin (v.)) + formative or agential *-thro. The connection with the root is more transparent in other Germanic cognates (such as Middle Low German, Middle Dutch, Middle High German, German spinne, Dutch spin "spider").
The male is commonly much smaller than the female, and in impregnating the female runs great risk of being devoured. The difference in sizes is as if the human female should be some 60 or 70 feet tall. [Century Dictionary]
Not the common word in Old English, which identified the creatures as loppe, lobbe, also atorcoppe, and, from Latin, renge. Another Old English word was gangewifre "a weaver as he goes," and Middle English had araine "spider" (14c.-15c., from French). In literature, often a figure of cunning, skill, and industry as well as poisonous predation; in 17c. English used figuratively for poisonousness and thread-spinning but also sensitivity (to vibrations), lurking, independence. As the name for a type of two-pack solitaire, it is attested from 1890. Spider crab is from 1710, used of various species; spider monkey is from 1764, so called for its long limbs.