Why is it called “physics”?
This question is so general that you can ask this one about any other word!
But let’s choose physics as you probably have studied it and maybe the word frightens you. (It is a good practice to study something that frightens you).
Every word we use right now is derived from some word in older languages. For example, much of English is derived from Ancient Greek and Latin language. And Sanskrit is the parent of many Indian native languages like Hindi, Marathi and others!
Physics word is derived from Ancient Greek word phusikḗ which according to Wikipedia means knowledge of nature.
Think about physics and what topics and concepts you learn in it. Everything that you learn in it is related to nature. How stuff behaves under force, how atoms work, how electricity influences the world around it and much more. So it makes sense to call this discipline by its meaningful name derived from Ancient Greek. Now can you call it something else?
Sure! In Hindi and other Indian languages, the word भौतिकी is used to mean what Physics is in English. Now that word is derived from Sanskrit!
Now, another deeper question is where did the Ancient Greeks come upon phusikḗor Ancient Indians come upon भौतिक? We are getting near the roots here.
When you trace some word and its history like the word physics here, in the end you will come down to the fact that some person or some group of persons must have decided to make some particular sequence of sounds and denote by some particular sequence of symbols of languages and then that is widely used by everyone else. If not widely, at least in the concerned circles.
That is how we get new words and meanings. And now you have an idea that when you don’t know some word, you can just trace back its history and find what it’s original meaning was.
Just for fun, we found what Physics is called and written as in different languages on Earth. Enjoy: