a large light-coloured antelope, Addax nasomaculatus, having ribbed loosely spiralled horns and inhabiting desert regions in N Africa: family Bovidae, order Artiodactyla 
WordReference Random House Unabridged Dictionary of American English © 2025
ad•dax 
(ad′aks),USA pronunciation n. 
- Mammalsa large, pale-colored antelope, Addax nasomaculatus, of North Africa, with loosely spiraled horns.
 
- some language of ancient North Africa
 - Latin, presumably
 - 1685–95
 
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