Definitions for "Liquidus"
When heated, most alloys change gradually from being totally solid to being totally liquid over an extended temperature range. The liquidus is the temperature at which the alloy is totally liquid. Note that in the case of eutectic materials, there is no such pasty range See solidus and pasty range.
Temperature at which an alloy becomes fully liquid. See also ‘solidus'
On a graph of temperature vs composition, a diagram showing the maximum solubility of a solid component or phase in the liquid phase.
Keywords:  stable, above, substance, line
a line above which the substance is stable in a liquid state