This is the 10373rd most frequent Portuguese word.
excepcionalmente
Exceptionally.
The word "excepcionalmente" is used here as an adverb to describe the action of waking up earlier than the usual time, emphasizing the uncommon occurrence.
Hoje, eu acordei excepcionalmente cedo.
Today, I woke up exceptionally early.
In this sentence, "excepcionalmente" is indicating an action taken out of the ordinary due to an extraordinary circumstance, namely the rain.
Excepcionalmente, o evento foi cancelado por causa da chuva.
Exceptionally, the event was canceled because of the rain.
Here, the usage of "excepcionalmente" emphasizes the remarkable rapidity in the student's learning process.