Difficult or impossible to break or separate into parts.

Roget 46: cohesive, adhesive, adhering, cohering etc. v.; tenacious, tough; sticky etc. 352.    united, unseparated, unsessile^†, inseparable, inextricable, infrangible^†; compact etc. (dense) 321.    ... show more

Roget 321: dense, solid; solidified etc. v.; caseous; pukka^†; coherent, cohesive etc. 46; compact, close, serried, thickset; substantial, massive, lumpish^†; impenetrable, impermeable, nonporous, imporous^†; incompressible; constipated; concrete etc. (hard) 323; knotted, knotty; gnarled; crystalline, crystallizable; thick, grumous^†, stuffy.    undissolved, unmelted^†, unliquefied^†, unthawed^†.    indivisible, indiscerptible^†, infrangible^†, indissolvable^†, indissoluble, insoluble, infusible.    ... show more

Not capable of being violated or infringed:
— Infrangible human rights.

synonyms: absolute, inviolable.