trep ‧ i ‧ da ‧ tion /ˌtrepəˈdeɪʃ ə n, ˌtrepɪˈdeɪʃ ə n/ BrE AmE noun [uncountable]
[ Date: 1400-1500 ; Language: Latin ; Origin: trepidatio , from trepidare 'to shake' ]
a feeling of anxiety or fear about something that is going to happen:
With some trepidation, I opened the door.