arachnoid

nouns

the middle of the 3 meninges
arachnoid, arachnoid membrane
air-breathing arthropods characterized by simple eyes and four pairs of legs
arachnid, arachnoid

adjectives

relating to or resembling a member of the class Arachnida
arachnidian, arachnoid, spiderlike, spiderly, spidery
pertains to
class Arachnida