adamant

determined insistent intransigent resolute rigid stubborn uncompromising

firm immovable pat set stiff

fixed hang-tough hanging tough hard-nosed inexorable inflexible obdurate relentless set in stone standing pat unbendable unbending unrelenting unshakable unswayable

flexible irresolute lenient weak willing yielding

indefinite movable moving soft unfixed

pliant submissive supple

tough

adamantine flinty impenetrable indestructible rock-hard unbreakable

flexible pliant soft submissive supple yielding