What does Moneme mean This word is frequently used by detective Poirot in the series?

In Agatha Christie's Poirot series, the term "moneme" is used to refer to a single unit of meaning, akin to a Word or a concept that conveys a specific idea. Poirot often employs this term to emphasize the importance of details in unraveling complex cases, highlighting how each piece of information contributes to the overall understanding of a situation. It reflects his meticulous approach to detective work, where every small element plays a crucial role in solving the mystery.