Legacy interface refers to an outdated technology or system that is still in use. Some synonyms for legacy interface are archaic interface, old-fashioned interface, outdated interface, and ancient interface. These terms are used to describe technology that has been replaced by newer and more advanced systems. Legacy interfaces are known for their inefficiency, lack of flexibility, and the difficulty of maintaining them. They are often associated with high costs of upgrading, limited support, and compatibility issues. The use of legacy interfaces can create hindrances in the modernization of the IT infrastructure of any organization. Overall, it is better to replace legacy interfaces with modern interfaces that offer more efficient and cost-effective solutions.