inseparable

adj

1. Unable to be separated; bound together permanently.

   “People of unalterable ideas still insisted upon calling him "Sergeant" when they met him, which was in some degree owing to his having still retained the well-shaped moustache of his military days, and the soldierly bearing inseparable from his form.”

   “In the old days, to my commonplace and unobserving mind, he gave no evidences of genius whatsoever. He never read me any of his manuscripts, […] and therefore my lack of detection of his promise may in some degree be pardoned. But he had then none of the oddities and mannerisms which I hold to be inseparable from genius, and which struck my attention in after days when I came in contact with the Celebrity.”

   “=This detail is one of the reasons which made a single, modern signalbox and the marshalling yard inseparable features in the modernisation of the Perth facilities. A central control point rather than 13 individual boxes, was essential to integrate with other movements the greatly increased flow of freight traffic through the station area.”

noun

1. Something that cannot be separated from something else.

   “Jayanta does so in answering an opponent who declares that the very idea of a relation between two inseparables is self-contradictory. How can inseparability and relation be reconciled?”