Just something I made up when promoting that EU should make CPU's . So its exactly what you say a merge of CPU and EU :-)
Ah okay, I was thinking something like Central Processing Embedded Units.
Google says it's "CPEU most commonly stands for Continuing Professional Education Unit, a credit system used by dietitians and nutrition professionals.". Yeah, not sure how that is related to RISC-V. Perhaps we should eat RISC-V powered nanobots to, uh, future sci-fi something?