Nephrism is a made-up word that doesn't have a real meaning in English.
It's like a secret code word that doesn't mean anything to most people.
Examples:
I made up a funny word, nephrism!
Nephrism is a silly word that I like to say.
Do you know what nephrism means? It doesn't mean anything!
I told my friend that nephrism is the word of the day.
In my made-up language, nephrism means 'hello'.
Nephrism is a word I made up for when I don't know what to say.