pertinacious

pertinacious is an   Adverb

Definition:

[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.

Synonyms: