Aush can mean several different things depending on the region.
In Iran and other areas influenced by Persian cuisine, aush (or ash) refers to a traditional Persian thick soup, often made with noodles, beans, herbs, and sometimes meat. One of the most famous examples is aush reshteh. In Persian cuisine, "aush" is a general term for soups, usually enriched with a variety of vegetables and herbs.
In Pakistan, the word aush refers to a type of noodle dish more akin to a stew or broth-based meal, often with noodles or dumplings. The term is less common in everyday use compared to its prominence in Persian cuisine, but in some areas influenced by Persian culture, such as parts of Khyber Pakhtunkhwa and Balochistan, it can describe dishes with similar noodle and soup elements.