in a way that shows that you are sad [= unhappily]:
Peter shook his head sadly.
2 [sentence adverb]
Sadly, the business failed.
very much - used when talking about bad situations or states:
The garden's been sadly neglected.
Good restaurants were sadly lacking.
He was a popular man who will be sadly missed.
I'm afraid you're going to be sadly disappointed.
If you think you'll get any money from him, you're sadly mistaken.