decide A2

/dɪˈsaɪd/ To make a choice about what to do after thinking about it.

decisively C2+

/dɪˈsaɪsɪvli/ in a firm and conclusive manner

decidable C2+

/dɪˈsaɪdəbəl/ able to be decided; in logic, solvable by an algorithm

decidedly C2+

/dɪˈsaɪdɪdli/ definitely and unmistakably

decisiveness C2+

/dɪˈsaɪsɪvnəs/ the quality of being firm and prompt in deciding