NSW Selective & Scholarship
Pertinacious
adjective/per-tin-AY-shus/
A pertinacious person holds on to a purpose or opinion with stubborn determination.
In contextHer pertinacious effort to master the violin finally paid off at the concert.
Remember it
It shares roots with 'tenacious' — both mean holding on and refusing to let go.
Use it well
Can be admiring (determined) or critical (stubborn), so the context must show which.