What is an Indian onion if such thing?

There is no specific type of onion called an "Indian onion." The term is likely used in a few different ways:

* A general term for onions grown in India: India is a major producer of onions, and several varieties are grown there. So, "Indian onion" could refer to any of these varieties, such as:

* Red onions: Popular in Indian cuisine, often used in chutneys, salads, and as a garnish.

* White onions: Commonly used in curries and other dishes, adding a sharper flavor.

* Shallots: A smaller variety with a delicate flavor, used in various dishes.

* Spring onions: The young green shoots of the onion plant, often used in stir-fries and salads.

* A specific variety of onion grown in India: Some regions of India may have specific varieties of onion with unique names and characteristics. However, these names are not widely known outside of India.

* A slang term for a particular type of onion: In some regions or communities, "Indian onion" might be used to refer to a specific variety or style of onion, but without a wider context, it's impossible to know for sure.

To understand what "Indian onion" refers to, you'd need more context:

* Where did you hear the term? The region or community can give clues.

* What was the context? Was it a recipe, a food market, or a conversation about onions?

Without more information, it's impossible to say precisely what "Indian onion" means.