Source : Webster's Revised Unabridged Dictionary (1913)

Dandelion \Dan"de*li`on\, n. [F. dent de lion lion's tooth, fr.
   L. dens tooth + leo lion. See {Tooth}, n., and {Lion}.]
   (Bot.)
   A well-known plant of the genus {Taraxacum} ({T. officinale},
   formerly called {T. Dens-leonis} and {Leontodos Taraxacum})
   bearing large, yellow, compound flowers, and deeply notched
   leaves.

Source : WordNet®

dandelion
     n : any of several herbs of the genus Taraxacum having long tap
         roots and deeply notched leaves and bright yellow flowers
         followed by fluffy seed balls [syn: {blowball}]