persistent vs dour

persistent and dour both are adjectives.

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

As adjectives, persistent and dour are synonyms defined as:

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

persistent (adjective)	dour (adjective)
retained; not shed	showing a brooding ill humor
never-ceasing	stubbornly unyielding
stubbornly unyielding	harshly uninviting or formidable in manner or appearance
continually recurring to the mind