Long-continuing is a term used to describe something that has lasted for a considerable amount of time. However, there are many other words and phrases that can be used to convey the same meaning. Some synonyms for long-continuing include "ongoing," "persistent," "prolonged," "continuous," "enduring," and "unceasing." Each of these words emphasizes the idea of something that has been going on for a lengthy period without interruption. Additionally, phrases such as "for a long time," "over an extended period," and "throughout an extended duration" can also be used in place of long-continuing to express the same idea. By using these synonyms, you can add variety to your writing while still conveying the same message.