Source : Webster's Revised Unabridged Dictionary (1913)

Sympetalous \Sym*pet"al*ous\, a. [Pref. sym- + petal.] (Bot.)
   Having the petals united; gamopetalous.

Source : WordNet®

sympetalous
     adj : having a corolla composed of partially or wholly fused
           petals forming a corolla shaped like a tube or funnel
           [syn: {gamopetalous}]