inflexible

modif.

1. Stiff

   rigid, hardened, unbendable, taut; see firm 2, stiff 1.

2. Firm of purpose

   implacable, resolute, obdurate, adamant, stubborn, unyielding, unshakable, immovable, determined, unrelenting, unalterable, fixed, ironclad; see also obstinate, resolute 2.

inflexible implies an unyielding or unshakable firmness in mind or purpose, sometimes connoting stubbornness his inflexible attitude; adamant implies a firm or unbreakable resolve that remains unaffected by temptation or pleading adamant to her entreaties; implacable suggests the impossibility of pacifying or appeasing implacable in his hatred; obdurate implies a hardheartedness that is not easily moved to pity, sympathy, or forgiveness her obdurate refusal to help