Noah Webster's New International Dictionary of the English Language

1. (a.) Not dissoluble; not capable of being dissolved, melted, or liquefied; insoluble; as few substances are indissoluble by heat, but many are indissoluble in water.

2. (a.) Incapable of being rightfully broken or dissolved; perpetually binding or obligatory; firm; stable, as, an indissoluble league or covenant.