An inkhorn term is an old-fashioned word that was once used by people who wanted to sound very smart and educated. These words were usually borrowed from other languages like Latin or Greek, and they were often very long and complicated. Nowadays, people don't use inkhorn terms as much because they can be hard to understand and people prefer to use shorter, simpler words. It's kind of like trying to use big words to impress your friends, but it's usually better to just speak plainly so everyone can understand you.