trep·i·da·tion
noun/ˌtrepɪˈdeɪʃn/
/ˌtrepɪˈdeɪʃn/
[uncountable] (formal)- great worry or fear about something unpleasant that may happen
惊恐；恐惧；惊惶；不安 - He knocked on the door with some trepidation.
他有些忐忑地敲了敲门。
Word Originlate 15th cent.: from Latin trepidatio(n-), from trepidare ‘be agitated, tremble’, from trepidus ‘alarmed’. - He knocked on the door with some trepidation.