'Spider' is 'the spinner' — from Proto-Germanic *spinnan. Kin to 'spin,' 'spindle,' and 'spinster.'
An eight-legged predatory arachnid with an unsegmented body, most kinds of which spin webs to capture insects.
From Old English 'spīþra' (spider), from Proto-Germanic *spinþrō, an agent noun from *spinnaną (to spin) — literally 'the spinner' or 'spinning creature.' The formation is exactly parallel to 'weaver' from 'weave': a spider is named for its defining action of producing thread. The Old English root verb 'spinnan' (to spin) derives from PIE
The word 'spinster' (originally a woman who spins thread) and 'spider' share the same Proto-Germanic root *spinnaną (to spin). An unmarried woman was called a 'spinster' because spinning was the default occupation for unmarried women in medieval households. The spider and the spinster are both, etymologically, 'spinners' — one