An object becomes molten when it's heated up and turns into liquid. Imagine melted chocolate that's too runny to hold its shape.
When we say something is molten, we usually mean it's hot and gooey like lava from a volcano or the metal that's being poured out of a furnace at a factory. But it can also refer to things that are liquid but not necessarily scorching hot, like honey when it's been left in the sun for too long. In both cases, molten describes something that's lost its solid shape and become fluid.
To change (or to be changed) from a solid state to a liquid state, usually by a gradual heat.
Example: I melted butter to make a cake.
Melted.
Example: molten metal
