Formal:
* زباله (Zibaleh) - This is the most common and neutral word for trash.
* آشغال (Ashghal) - This word is considered slightly more informal than "zibaleh," but still acceptable in most situations.
Informal:
* خرت و پرت (Khorte o Porte) - This literally translates to "junk and stuff" and is a more colloquial way to say "trash."
* خرت و پرت (Khorte o Porte) - This is similar to "khort o porte," but with a more negative connotation. It's often used to refer to things that are worthless or of low quality.
Slang:
* گُل (Gol) - This is a slang word for trash, often used jokingly.
The best way to choose the right word depends on the context and your relationship with the person you're speaking to.
For example, you would use "zibaleh" when talking about trash with a stranger or in a formal setting, but "khort o porte" might be more appropriate with friends or family.