Source : Webster's Revised Unabridged Dictionary (1913)

Urticaceous \Ur`ti*ca"ceous\, a. (Bot.)
   Of or pertaining to a natural order ({Urticace[ae]}) of
   plants, of which the nettle is the type. The order includes
   also the hop, the elm, the mulberry, the fig, and many other
   plants.

Source : WordNet®

Urticaceae
     n : a family of plants of order Urticales including many nettles
         with stinging hairs [syn: {family Urticaceae}, {nettle
         family}]