This is the 1563rd most frequent Chinese word.
发动
To start, launch, initiate, or mobilize.
Here, '发动' means 'to mobilize,' used to describe organizing or motivating a group of people.
我们需要发动全员的力量来完成这个任务。
We need to mobilize the efforts of all members to complete this task.
Here, '发动' means 'to start,' referring to starting a vehicle.
他发动了汽车，准备出发。
He started the car, getting ready to depart.
In this context, '发动' translates to 'to initiate' or 'to launch,' as it pertains to starting a war.