dogged

(verb) go after with the intent to catch. Synonyms: chase, chase after, trail, tail, tag, give chase, dog, go after, track. Examples: "The policeman chased the mugger down the alley." "The dog chased the rabbit."

(adj) stubbornly unyielding. Synonyms: dour, persistent, pertinacious, tenacious, unyielding. Examples: "Dogged persistence." "Dour determination." "The most vocal and pertinacious of all the critics." "A mind not gifted to discover truth but tenacious to hold it"- t.s.eliot." "Men tenacious of opinion."