Continuous-time is a term that refers to a mathematical concept that deals with functions that are defined over an infinite interval of time. It is often used in relation to systems that are modeled with differential equations or calculus. There are several synonyms for continuous-time that can be used interchangeably, including continuous-domain, time-continuous, and continuous-space. These terms all convey the same idea of an uninterrupted flow of time or space. They are commonly used in physics, engineering, and other fields that deal with complex systems that require modeling over a continuous spectrum. Overall, these synonyms offer flexibility and precision in discussing the properties of dynamic systems over time.