pertinacious

Adjective

Synonyms: dogged dour persistent tenacious unyielding

WordNet 3.0

Adjective (1)

stubbornly unyielding“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”Synonyms: dogged dour persistent tenacious unyielding

Webster's Dictionary (GCIDE)

Pertinacious \Per`ti*na"cious\, a. [L. pertinax, -acis; per + tenax tenacious. See Per-, and Tenacious.]

1.Holding or adhering to any opinion, purpose, or design, with obstinacy; perversely persistent; obstinate; as, pertinacious plotters; a pertinacious beggar. [1913 Webster]

2.Resolute; persevering; constant; steady. [1913 Webster]

Diligence is a steady, constant, and pertinacious study.— South.[1913 Webster]

Syn: Obstinate; stubborn; inflexible; unyielding; resolute; determined; firm; constant; steady. [1913 Webster] -- Per`ti*na"cious*ly, adv. -- Per`ti*na"cious*ness, n. [1913 Webster]