When a person, place or thing, unexpectedly dissolves into a puddle of liquid. Sometimes bursting like a water balloon or melting into a puddle, most likely killing them. Direct opposite of spontaneous combustion.
In the first X-men movie, the character Senator Kelly died by Spontaneous Liquidation.
Or
I was watching two men climb down a ladder when suddenly the first man ignited in spontaneous combustion, luckily at the same time the man man burst in spontaneous liquidation, putting the flames out.