Below is one of the prayers which the priest says before reading the Gospel in the Tridentine Mass.
Munda cor meum, ac labia mea, omnípotens Deus, qui labia Isaíæ Prophétæ cálculo mundásti igníto: ita me tua grata miseratióne dignáre mundáre, ut sanctum Evangélium tuum digne váleam nuntiáre. Per Christum, Dóminum nostrum. Amen.
My intuition tells me that digne is an adverb modifying valeam, hence "so that I may worthily be able to announce your holy Gospel." But when I looked up digne in my Latin-English dictionary, it isn't listed as an adverb.