Pĕr'ti-nā'cioŭs, a.

a. [Lat. pertinax, pertinacis, from the prefix per, through, and tenax, tenacious; Fr. & It. pertinace, Sp. & Pg. pertinaz.]

1. Holding or adhering to any opinion, purpose, or design, with obstinacy; obstinate; perversely resolute; as, pertinacious in opinion.
2. Resolute; firm; constant; steady.

Diligence is a steady, constant, pertinacious study. South. Syn. — Obstinate; stubborn; inflexible; unyielding; resolute; determined; firm; constant; steady.