Functional designs refer to designs that efficiently fulfill their intended purpose. There are several synonyms for functional designs, including utilitarian designs, practical designs, purposeful designs, and efficient designs. Utilitarian designs prioritize utility over aesthetics, thus resulting in a simple and straightforward design. Practical designs prioritize usefulness and functionality. Purposeful designs are those designed with a specific motive and intention. Efficient designs prioritize maximum functionality with minimal wastage of resources. Overall, functional designs prioritize the usefulness and practicality of a design over its appearance, ensuring that the design performs its intended function effectively.