Ajwain, also known as carom seeds, are a popular Indian spice with a pungent, slightly bitter flavor and thyme-like aroma, often used in curries, snacks, and breads. 
Here's a more detailed description:
Appearance:
Ajwain seeds are small, tear-shaped, and light brown in color, resembling celery seeds. 
Taste and Aroma:
They have a pungent, slightly bitter flavor with a thyme-like aroma, often described as a blend of oregano and anise. 
Uses:
Culinary: Ajwain seeds are used in various Indian dishes, including curries, snacks like Pakora and onion bhajia, and breads. 
Other Uses: They are also used in pickling and as a flavoring agent for meat or fish. 
Plant:
Ajwain is a fragrant annual plant native to India, also grown in Afghanistan, Egypt, Iran, and Pakistan. 
Other Names:
Ajwain is also known as carom seeds, bishop's weed, or lovage. 
Medicinal Properties:
Ajwain is also favored for its medicinal properties and is used by some people for its antiseptic properties as well as for indigestion. 
Chemical Composition:
The major component of ajwain oil is thymol, which has antimicrobial and antioxidant properties. 
Allergens:
Ajwain seeds are generally safe for vegetarians, but may contain traces of gluten, celery, sesame, milk, tree nuts, peanuts, soya and sulphites.