Less certain, unclear, uncertain, ambiguous, doubtful, dubious, incredulous, mistrustful, suspicious, unbelieved, unconvinced, unsure, hesitant, indecisive, skeptical, unconfident, hesitant, vacillating, wavering, indecisive, unpredictable, irregular. These words are antonyms to "more surmised," an adjective that means forming an opinion or idea without firm evidence, guessing. To express the opposite sentiment of a word, it is often helpful to use its antonym. In this case, it conveys less certainty or less than expected guesswork. One can use these antonyms to describe situations where there is an insufficient amount of evidence to form a decisive conclusion.