Definition from Wiktionary, the free dictionary
- In a way that causes surprise because it is unexpected, or unusual.
- The house was surprisingly small for such a numerous family.
- Not surprisingly, the electrician didn't come at the time he had said.
- 2012 April 23, Angelique Chrisafis, “François Hollande on top but far right scores record result in French election”, the Guardian:
- François Hollande has moved a step closer to becoming the first Socialist president of France in a generation by beating the incumbent, Nicolas Sarkozy, in the first round of elections. But the surprisingly high vote for the extreme-right candidate, Marine Le Pen, boosted the overall figures for the right and meant that the final runoff vote on 6 May remains on a knife edge.
Usage notes 
- This adverb is more often used to modify an adjective than a verb