what is meaning of the 'epipetalous'?

epipetalous are those flowers in which the androecium (anther) is attached with the petals of the flower bt since in some plants like lily sepals and petals are the same which are called perianth and when anther is attached to perianth it called epiphyllous  

Borne on or attached to the petals or corolla, as the stamens of the petunia.

Epipetalous is the condition in which the stamens are attached to the petals of the flower. If the stamens are attached to the perianth then it is called epiphyllous.