What is physics?
Precisely define the most fundamental measurable quantities in the universe (e.g., velocity, electric field, kinetic energy). The effort to find the most fundamental description of the universe is a quest that has historically always been a big part of physics, as can be seen in the comic image below.
Find relationships between those fundamental measured quantities (e.g., Newton’s Laws, conservation of energy, special relativity). These patterns and correlations are expressed using words, equations, graphs, charts, diagrams, models, and any other means that allow us to express a relationship in a way that we as humans can better understand and use.
OK, so boiling physics down to only two things is admittedly a bit of a gross simplification and glosses over some of the finer points of what physicists do and how they do it. But trying to describe a complex universe with simple and useful clarifying laws is what physics is all about. So maybe trying to describe the complex activity of what physicists do with a simple and clarifying definition isn’t such a bad idea after all.