Definition
To mix a solid, liquid, or gas uniformly into a liquid (the solvent) so that it spreads through the liquid at the molecular level and is no longer present as a separate substance.
Plain English
To mix something completely into a liquid so it disappears into it and becomes part of the liquid itself, rather than sitting as a separate piece or layer.
Context Anchor
Seen in aircraft maintenance, cleaning, fuel, oil, battery, and chemical-use discussions.
Derivation
From Latin 'dissolvere', meaning 'to loosen apart' (dis- 'apart' + solvere 'to loosen'). The original sense of loosening something into its parts fits the technical idea: the substance is broken down and spread evenly through the liquid.
Why Pilots Care
Dissolving clouds or fog often signals improving conditions that may allow a shift from IFR to VFR flight or reduce the risk of IMC encounters.
Intuition Check
Dissolve does not simply mean “disappear.” In aviation maintenance, it means a material mixes into a liquid evenly enough that it is no longer separate.
Example Sentence 1
Water vapor can dissolve into aviation fuel, which is why fuel tanks are checked for water during preflight.
Example Sentence 2
Forecasters expected the radiation fog to dissolve by mid-morning, restoring VFR conditions along the route.