surprisingly
adv.used to say that something is unexpected or different from what you thought. You use it to show that a fact is a bit of a shock.
adv.in a manner that causes astonishment or wonder because it is unexpected. Often functions as a disjunct to express the speaker's attitude toward the following statement.
“The exam was surprisingly easy.”
“Surprisingly, the small restaurant was completely full on a Tuesday night.”
“The results of the study were surprisingly consistent across different age groups, despite the researchers' initial hypothesis that older participants would respond more conservatively.”
When modifying an entire sentence, it usually appears at the beginning followed by a comma; otherwise, it sits immediately before the adjective or adverb it modifies.
As an adverb, it must modify an adjective, verb, or another adverb, rather than a noun directly.
Usage surprisingly difficult
From surprising + -ly.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.