ironclad (n.)
ironclad (adj.)
- armor-plated
- armored
- constant
- dour
- firm
- fixed
- fundamentalist
- hard
- hidebound
- immovable
- immutable
- inalterable
- inexorable
- inflexible
- invariable
- iron
- mailed
- muscle-bound
- obdurate
- obstinate
- orthodox
- panoplied
- procrustean
- puritanic
- relentless
- rigid
- rigorous
- rockbound
- stiff
- straightlaced
- straitlaced
- stubborn
- unalterable
- unbending
- uncompromising
- unmodifiable
- unrelenting
- unyielding
