immovable

Synonyms: adamant constant dead set on dug in fast firm hard-nosed immobile immotile immutable impassive inflexible intransigent locked in motionless obdurate quiescent resolute rooted secure set set in concrete set in stone solid stable stand pat stationary steadfast stick to guns stuck tough nut unalterable unchangeable uncompromising unmodifiable unshakable unwavering unyielding

Antonyms: mobile movable moving unfixed