Source : Webster's Revised Unabridged Dictionary (1913)

Urtica \Ur*ti"ca\, n. [L., a nettle.] (Bot.)
   A genus of plants including the common nettles. See {Nettle},
   n.

Source : WordNet®

Urtica
     n : a nettle yielding fiber resembling flax [syn: {genus Urtica}]