What is second largest city?

The question lacks specific context, so it's difficult for me to determine which city is the second largest. It depends on the geographical area or country being considered. There are numerous second largest cities in different parts of the world, including:

- Mumbai, India

- Mexico City, Mexico

- Cairo, Egypt

- London, United Kingdom

- Los Angeles, United States

- Beijing, China

- Jakarta, Indonesia

- Karachi, Pakistan

- Istanbul, Turkey

- Buenos Aires, Argentina

If you are interested in knowing the second largest city in a specific country or region, please specify that in your inquiry so I can provide you with accurate information.