決める
きめる (kimeru)
to decide, to determine
verb (ichidan)
Example
来年の旅行先を決めなければなりません。
らいねんのりょこうさきをきめなければなりません。
Rainen no ryokousaki wo kimenakereba narimasen.
I have to decide on next year's travel destination.
A very useful verb for expressing decision-making. Often paired with を particle for the thing being decided.