Hi, Grace. Thanks so much for this suggestion. One of the toughest parts of writing this thesaurus was figuring out which emotions to highlight. So many of them are similar to one another—synonymous, even—and including all of them would’ve created an enormous book that no one would have been able to afford :). So we had to make tough choices about content. For trepidation, we chose to go with Apprehension; they’re super similar, and we thought the latter was more commonly used and would be easier for readers to find. So you might want to check out that entry. Have a great day!