Unassailable rhymes with:
salable, saleable, unsalable, unsaleable, available, inhalable, salable, saleable, unavailable, unsalable, unsaleable
Unassailable sounds like:
unsalable, unsaleable, unsolvable
salable, saleable, unsalable, unsaleable, available, inhalable, salable, saleable, unavailable, unsalable, unsaleable
unsalable, unsaleable, unsolvable