Maximal Extractable Value
The acronym MEV refers to two names:
- In Proof of Work (Pow), MEV stands for Miner Extractable Value.
- In Proof of Stake (PoS), MEV stands for Maximal Extractable Value.
This is because there is no "miner" in PoS. To preserve the acronym MEV, "maximal" was chosen as the "M". I found this explanation in this article:
Maximal extractable value (MEV) | ethereum.org
Maximal extractable value (MEV) - ethereum.org