Although George's guess of "enterprise" is reasonable, my money is on "esri," with a very small chance "enhanced."
The earliest mentions of "multiversioned views" that I recall are from ArcGIS 9.2, which coincidentally the ArcGIS 9.2 Desktop Help is still available online (kudos to Esri for keeping the historical record alive online). From ArcGIS Desktop Help 9.2 - Using multiversioned views:
What are multiversioned views?
Multiversioned views incorporate database views, stored procedures, triggers, and functions to access a specified version of data in a geodatabase table using structured query language (SQL).
In the early days, the documentation suggested using either a "mv_" prefix or "_mv" suffix:
- At a command prompt, execute the sdetable function to create a multiversioned view.
sdetable –o create_mv_view –T permits_mv –t permits –i 4400 –D code –u sarja –p not4u
The "mv" prefix or suffix made sense given the name of the feature was "multiversioned view." However, around that same time "mv" started becoming associated with "materialized views." As important as geodatabases may be to us GIS users, the non-spatial use of databases dominates the spatial use of databases, so most people in the database world would associate "mv" with "materialized view" and not "multiversioned view."
There was a brief period after transitioning from "mv" where Esri adopted "vw," which is a standard suffix or prefix for any database view. I believe it was also around this same time that Esri moved away from "multiversioned views" and starting use just "versioned views." Although "vv" is a logical abbreviation for "versioned view," my guess is people didn't like it because it might be too easy for people to confuse "vv" for "w".
Similar to Esri JSON, Esri JS, and other standard terms that Esri prefixes with their name, my guess is that "e" in "evw" is for Esri. Also, the change from "SDE" to "Enterprise geodatabase (EGDB)" came many years after the switch to "evw" so I don't think the word "enterprise" was the motivation.
