Sentence:  Somewhat to his <WSD>surprise</WSD> he found that one girl , whom he would never have considered for the job since she had appeared somewhat mousy and also had been in the office a relatively short time , did the most outstanding job of playing the role of receptionist , showing wit , sparkle , and aplomb . 
Meaning of the word marked with <WSD> tags:  the astonishment you feel when something totally unexpected happens to you