means Spiders are eight-legged arachnids (not insects) that spin silk, hunt prey, and turn up uninvited in the corners of rooms everywhere.

from From Old English "spīþra," which traces back to the verb "spinnan" — to spin. So the name simply means "the spinner," a creature defined by what it does. The same spinning root threads through related Germanic words and gives us "spindle" and "spin" itself; the spider was, quite literally, named for its craft.