Synonyms for unyielding

adamant, demanding, determined, dogged, firm, hard, hard-line, immovable, impregnable, indomitable, industrious, inflexible, insistent, insurmountable, intransigent, invincible, invulnerable, obstinate, over-exacting, persevering, persistent, relentless, resolute, rigid, single-minded, solid, steadfast, stiff, strong-minded, stubborn, tenacious, unadaptable, unbendable, unbending, unbent, uncompromising, unconquerable, undeviating, unflagging, unshakable, unshakeable, unstoppable, unswerving, unwavering, willful