Sentence:  She reached it soon after half-past two. She found its gloomy nineteenth-century façade, black with the smuts of ninety years, a little daunting, and mounted its broad steps in some <WSD>trepidation</WSD>. But she rang the bell hard and knocked firmly. 
Meaning of the word marked with <WSD> tags:  A fearful state; a state of concern or hesitation.