This is the 722nd most frequent Icelandic word.
ótrúlega
Incredibly.
In this example, "ótrúlega" modifies "skemmtilegt" (enjoyable) to stress how exceptionally enjoyable the evening was.
Við höfðum ótrúlega skemmtilegt kvöld.
We had an unbelievably enjoyable evening.
Here, "ótrúlega" functions as an adverb intensifying the adjective "fallegt" (beautiful), emphasizing the extraordinary beauty of the sunset.
Þessi sólarlag er ótrúlega fallegt.
This sunset is unbelievably beautiful.
In this sentence, "ótrúlega" is used as an adverb modifying the adjective "hæfileikarík" (talented) to intensify the meaning, signifying a high degree of talent.