Meaning of ARACHNIDA in English

ARACHNIDA

-nədə noun plural

Usage: capitalized

Etymology: New Latin, from arachn- + -ida

1. : a large class of arthropods including scorpions, spiders, mites, and related forms all lacking wings and free first antennae and having highly modified prehensile second antennae and most being also air-breathing by means of tracheae or book lungs and having head and thorax fused to form a cephalothorax that bears six pairs of appendages consisting of four pairs of walking legs, a pair of pedipalpi variously specialized in different groups, and a pair of buccal chelicerae often provided with poison glands

2. in former classifications : a more extensive group including the Arachnida together with the king crabs, tongue worms, sea spiders, water bears, and sometimes the extinct eurypterids

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.