The verb “padat” means, to fall. When you put a prefix on the front of this verb though, all kinds of things can change. It makes sense, but only after long and dilligent study and research (which I perform nightly over beer at the local hospoda). The prefix “za” can mean, behind. So clearly, the word “západ” means, to fall behind. No – that’s not it at all! Zapad means west. I guess it’s because that’s the direction in which the sun seems to fall. Good thing the inventors of Czech weren’t too familiar with astronomy and physics, or we’d have a word like “direction that the sun appears to fall, but in reality we know the earth is revolving while the sun is stationary so we’ll call this earth rotation direction instead”.