Niño, hombre, varón are all types of men.
Niño is boy. Hombre is man.
Varón, you may be less familiar with, in general it means male. But it can also be used to mean a man of authority or respect.

Angosto was a word that confused me when I first heard it. It means narrow and is often used to describe streets as being narrow. Even after hearing it often for 3+ years, I think they mean a wide road. I have to take a moment and correct myself mentally.
Angosto is narrow, ancho is wide.

Tarde o temprano is an idiomatic expression that means sooner or later.
An example of its usage would be: Tarde o temprano los Delfines de Miami van a ganar un partido. Sooner or later the Miami Dolphins are going to win a game.

We run across the word inmundo quite a bit. It means something dirty or revolting. It is not just sucio, dirty, it is more, something vile and disgusting.

Often we are asked if we live in a casa rentada or casa particular. Particular here means a private home, or personally owned home.
It can also mean the same as it does in English, particular. More commonly though it is used to mean something that is private as opposed to commercial.