Electric-grade gel / silicone to provide physical protection for circuit boards from damage
... just the generic name ...

You might be looking for a &quot;conformal coating&quot; and/or &quot;potting compound&quot;

Conformal coating material is a thin polymeric film which conforms to the contours of a printed circuit board to protect the board's components. Typically applied at 25-250 μm1 thickness, it is applied to electronic circuitry to protect against moisture, dust, chemicals, and temperature extremes.


In electronics, potting is a process of filling a complete electronic assembly with a solid or gelatinous compound for high voltage assemblies by excluding gaseous phenomena such as corona discharge, for resistance to shock and vibration, and for the exclusion of water, moisture, or corrosive agents.

(my emphasis in both paragraphs)
Using either of the phrases  &quot;conformal coating&quot; and/or &quot;potting compound&quot; as a search term will find a range of available products.