This is the 4337th most frequent Japanese word.
動か
"動か" is not a standalone word but rather a stem of the verb "動かす," meaning "to move" or "to shift (something)."
Here, '動かなく' means 'not moving,' indicating the clock is not functioning properly.
時計が動かなくなった。
The clock has stopped working.
In this sentence, '動かす' means 'to move (something),' describing the act of relocating the box.
この重い箱を動かすのに助けが必要だ。
I need help to move this heavy box.
Here, '動かす' is used metaphorically to mean 'to advance or change (plans)' emphasizing progress.