Spacetimes, a term used in physics, refers to the four-dimensional space-time continuum that encompasses all events and objects in the universe. Some synonyms for spacetimes include "space-time fabric," "space-time geometry," "space-time continuum," and "space-time manifold." These terms are interchangeable and refer to the concept that space and time are not separate entities but are interconnected. Other words that relate to the same concept include "relativity," "gravity," and "curvature." It is important to note that these terms are technical and not commonly used in everyday language, but they play a crucial role in understanding the nature of the universe.