Not capable of being dissolved, melted or liquefied, as by heat or water. Few substances are absolutely indissoluble by heat; many are indissoluble in water.

That cannot be broken or rightfully violated; perpetually binding or obligatory; as an indissoluble league or covenant. The marriage covenant is indissoluble, except in certain specified cases.

Not to be broken; firm; stable; as indissoluble friendship; indissoluble bands of love.