Medical Dictionary
Main Entry:
Arach·ni·da Pronunciation:
&-'rak-n&d-& Function:
noun plural : a large class of arthropods that are mostlyair-breathing by means of trachea or book lungs, that include the spiders and scorpions, mites, and ticks, and that have a segmented body divided into two regions of which the anterior bears four pairsof legs but no antennae —
arach·nid /-n&d/ adjective or noun
