The term "future-proof" is often used to describe something that is resistant to becoming obsolete or outdated. However, there are several synonyms that can be used to convey the same meaning. For example, "future-ready" implies that something is well-prepared for what lies ahead. "Forward-thinking" implies that something has been designed with an eye towards the future. "Sustainable" implies that something is able to last and remain relevant for a long time. "Resilient" implies that something is able to adapt and withstand the challenges that the future may bring. No matter which term is used, the underlying message is that something is designed to withstand the test of time, and that it will remain relevant and useful well into the future.