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.
2. Resolute; persevering; constant; steady.
Diligence is a steady, constant, and pertinacious study. South.
Syn. — Obstinate; stubborn; inflexible; unyielding; resolute; determined; firm; constant; steady.
— Per′ti‐na″cious‐ly, adv. — Per′ti‐na″cious‐ness, n.