34 surely synonyms include it must be the case that, I believe that, assuredly, without question, don't tell me that … not …, and definitely. Surely is an adverb, and its antonyms are doubtfully and uncertainly. Here are some additional synonyms for "surely" with example sentences.
34 other ways to say surely.
Her story will surely appeal to many.
It will surely be a challenge.
She surely knows the answer to that question.
This is surely the best day of my life.
You are surely joking, right?