Surely synonyms such as doggedly, i believe that, certainly, confidently, and determinedly. Surely is an adverb, and its antonyms are doubtfully and uncertainly.
Another word for Surely
1. assuredly
- without question
- it must be the case that
- I believe that
- don't tell me that … not …
- assuredly
2. incontestably
3. securely