[jimminy]

I read it as "Solid State Hybrid" -Disk.

Which when regarded under the conventional drives at the time it was announced being primarily HDD's it makes it more clear.

You have an HDD that is a hybrid with solid state components. Logically clean cut, imo.

[DKnoll]

I'm being super pedantic here, but see how you said hybrid before solid state in your third sentence when explaining it? That's basically what I just suggested would be a clearer name.

[jimminy]

Likewise, I'm being pedantic.

Hybrid disk would be the generic term.

There has been work on liquid-state storage.

So Solid State becomes the adjective modifier for providing the classification of the type of Hybrid Disk.

You could in theory have a Liquid State Hybrid Disk, or a Liquid Solid State Hybrid Drive.