means Solubility is the degree to which one substance can dissolve into another to form a uniform mixture, usually how much of a solid, liquid, or gas a given solvent can hold.

from From the Latin 'solubilis,' meaning 'able to be dissolved or loosened,' built on 'solvere'—to loosen, release, or untie. That same 'solvere' gives us 'solve,' 'solution,' and 'dissolve,' all sharing the quiet image of something bound being set free. The '-ity' suffix, from Latin '-itas' by way of French, turns the quality into a measurable noun, so solubility is literally the 'loosen-ability' of a substance into its solvent.