An adverb meaning 'to that extent' or 'so much,' used to refer to a previously mentioned degree or manner and often to emphasize emotion or degree.
あんなに怒るとは思わなかった。
I didn't think he would get so angry.
あんなに遠いとは知らなかった。
I didn't know it was that far.
子どものころはあんなに元気だったのに、最近は疲れやすい。
I used to be that energetic as a child, but lately I get tired easily.
あんなに美味しい料理を久しぶりに食べた。
It's been a long time since I've eaten something so delicious.