This is the 16502nd most frequent Russian word.
самоходка
Self-propelled vehicle or equipment.
Here 'самоходка' refers to a vehicle equipped with its own means of propulsion.
Эта самоходка легко преодолевает любые препятствия.
This self-propelled vehicle easily overcomes any obstacles.
In this sentence, 'самоходка' is used to describe a military self-propelled vehicle, such as an artillery unit.
Он рассказал историю, как он управлял самоходкой в армии.
He told a story about how he operated a self-propelled vehicle in the army.
Here, 'самоходка' takes the meaning of a self-propelled agricultural machine.