a.
1.
Stubborn, dogged, contumacious, unyielding, inflexible, perverse, mulish, opinionated, opinionative, wilful, heady, headstrong, refractory, unruly, cross-grained, intractable, obdurate, persistent, self-willed, immovable, firm, resolute, pertinacious.
2.
Unyielding, immovable, stubborn, tenacious.