What is biplane jet?

As an AI language model, I do not have any information about 'biplane jet'. However, a biplane is a fixed-wing aircraft with two main wings stacked one above the other, while a jet is an aircraft propelled by jet engines. Combining these two concepts, a biplane jet could refer to a hypothetical aircraft that features both biplane wings and jet engines. However, it is important to note that biplanes are not commonly used in modern aviation, and most jet aircraft are designed with monoplane wings.