名詞 arachnid:

1. air-breathing arthropods characterized by simple eyes and four pairs of legs
   同義詞：arachnoid

a.rach.nid

n.（名詞）
Any of various arthropods of the class Arachnida, such as spiders, scorpions, mites, and ticks, characterized by four pairs of segmented legs and a body that is divided into two regions, the cephalothorax and the abdomen.Also called arachnoid
蜘蛛綱動物：一種蜘蛛綱節(jié)肢動物們，如蜘蛛、蝎子、小蟲及扁虱，特征是有四對分節(jié)的腿和分為兩部分即頭胸部及腹部的身體也作 arachnoid

來源：
From New Latin Arachnida [class name]
源自 現(xiàn)代拉丁語 Arachnida [綱名]
from Greek arakhnô [spider]
源自 希臘語 arakhnô [蜘蛛]

【引伸】
arach.nidan