Pleonasm is using more words than you need to, either accidentally or deliberately. An example of pleonasm? "She picked up the tiny little baby kitten."
The Greek root word in pleonasm is pleonazein, which describes something as more than enough. Used accidentally, a pleonasm is just long-winded wordiness, like a sentence that includes far more words than is necessary. Used on purpose, pleonasm is a tool used by writers and speakers to emphasize something or clarify an idea through repetition. This helps audiences remember main ideas as they listen or read.