This is the 1273rd most frequent German word.
enorme
"Enorme" in German means "enormous" or "huge" in English.
Here, 'enorme' is used as an adjective to emphasize the great magnitude of 'Leistung' (achievement).
Er hat eine enorme Leistung vollbracht.
He accomplished an enormous achievement.
In this sentence, 'enorm' describes the significant amount or size of 'Kosten' (costs).
Die Kosten für das Projekt waren enorm.
The costs for the project were enormous.
Here, 'enorm' is applied in an adverbial form ('enorm gestiegen') to describe the intensity of 'gestiegen' (risen).