Etymology for Atronach?

Solution 1:

We don't know

Atronachs are a subset of the Daedra. We know from the lore book Aedra and Daedra that "Aedra" and "Daedra" are Aldermi (i.e. Elvish) words meaning "ancestors" and "not our ancestors" respectively. However, no such etymology is given for "Atronach".

We also know that Atronach are also known as "Elemental Daedra" (Darkest Darkness) and the Atronach constellation is also known as the Golem (The Firmament). But in both these cases, these are clearly alternate names and not translations from another language.

There is unfortunately no clear out-of-universe etymology either. The word "atronach" is not a real word and has no obvious relation to another word. It appears to be an original creation of the developers of the series.