like a spider or arachnid:intelligent arachnoid killing machines
(also arachnoid membrane) Anatomy a fine, delicate membrane, the middle one of the three membranes or meninges that surround the brain and spinal cord, situated between the dura mater and the pia mater.
mid 18th century: from modern Latin arachnoides, from Greek arakhnoeidēs 'like a cobweb', from arakhnē 'spider'
arachnoid in other Oxford dictionaries
Definition of arachnoid in the US English dictionary