The antonyms for the word "more jokingly" are straightforwardly, seriously, earnestly, soberly, gravely, and solemnly. These words imply a lack of humor or levity in communication. If someone is communicating straightforwardly, they are being direct and to the point with no time for jokes. Similarly, if someone is speaking soberly or gravely, they are probably discussing a serious matter that is not appropriate for jokes. While it may be appropriate to be more jokingly in some situations, these antonyms suggest that there are times when humor is not appropriate, and we should communicate respectfully and with sincerity.