- arachnoid, arachnidian, spidery, spiderlike, spiderly - relating to or resembling a member of the class Arachnida
- arachnoid, arachnoid membrane - the middle of the 3 meninges
--1 is a kind of meninx, meninges
--1 is a part of leptomeninges - arachnid, arachnoid - air-breathing arthropods characterized by simple eyes and four pairs of legs
--2 is a kind of arthropod
--2 is a member of Arachnida, class Arachnida
--2 has particulars:harvestman, daddy longlegs, Phalangium opilio; scorpion; false scorpion, pseudoscorpion; whip-scorpion, whip scorpion; spider; acarine