liquidus

As a letter s

is the letter s with a.

As a noun liquidus is

(chemistry|physics) a line, in a phase diagram, above which a given substance is a stable liquid and below which solid and liquid are in equilibrium.

As nouns the difference between liquidus and liquids

is that liquidus is a line, in a phase diagram, above which a given substance is a stable liquid and below which solid and liquid are in equilibrium while liquids is plural of lang=en.