unyielding vs dour

unyielding and dour both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unyielding	No	Yes	No	No
dour	No	Yes	No	No

As adjectives, unyielding and dour are synonyms defined as:

Other synonyms of unyielding include dogged, persistent, pertinacious, tenacious.

unyielding (adjective)	dour (adjective)
resistant to physical force or pressure	showing a brooding ill humor
stubbornly unyielding	stubbornly unyielding
	harshly uninviting or formidable in manner or appearance