Extranjerismos no adaptados refers to loanwords from other languages that keep their original spelling and pronunciation e.g. "el bagel", which pronounces the "g" as such, even though it is followed by an "e".
Heteronyms are words that is spelt the same, but have a different pronunciation and meaning. An example in English is "gill":
So, heteronyms (heterónimos) would occur if a word under "extranjerismos no adaptados" has the same spelling as a native Spanish word. So, I just wanted to know some examples of these words.