1. arachnid n. a member of the family Arachnida, which principally includes animals with four pairs of legs and no antennae, such as spiders, scorpions, mites, and ticks 蛛形纲动物(诸如蜘蛛、蝎子、螨、蜱) My interest in arachnids began when I used to watch spiders build their gorgeous webs in the corners of the porch. 我过去常常观察蜘蛛在走廊的角落结网，其所结之网甚为奇妙，我对蛛形纲动物的兴趣油然而生。