conspiratorial /kənˌspɪɹəˈtɔːɹɪəl/ adjective2 •Pertaining to conspiracy or conspirators.His conspiratorial whispers were soft, but that just attracted more attention. •Believing in conspiracy theories.Conspiratorial thinking is another predictor of vaccine hesitancy, according to the 2018 study. — 2021 formsmore conspiratorial · most conspiratorial