Subarmalis in the literary sources

[Sean Manning]

The heretical thought occurs to me: Is there any text that specifically identifies subarmalis as a garment worn under armour or is this a modern assumption based on its supposed etymology?

And, if we don't "already know" that subarmalis has to be a garment worn under armor, would we ever see that arming doublet in the Vindolanda tablet, listed along with tallow and pepper, or in the Carlisle tablet, in the middle of the list of missing weapons?

As a so-so Latinist, I think that subarmalis is pretty obviously "thing under kit". Deductions like this are very common; social historians have a lot of terms like sarcinatrix and cabator which aren't used in literature and which they have to deduce from context. I'm not saying that the obvious meaning is right, but it is what I would guess if I encountered it in an inscription and weren't a militarist.

I have never encountered the Greek loan-word armus, and the PHI database gives mixed evidence. Its common in Augustan poets, who liked Greek words to show off their learning and help fit the metre, but also shows up in Pliny Maior and Columnella. Common compounds like armiger and Armilustrum all come from the neuter plural arma. Is there any evidence that armus as "the body part between the wrist and the shoulder" was common in Vulgar Latin? I don't think it survives in French or Italian.