Definition of pertinacious in English:

pertinacious

adjective

formal
  • Holding firmly to an opinion or a course of action:

    ‘he worked with a pertinacious resistance to interruptions’
    • ‘His enquiries were pertinacious.’
    • ‘He was a pertinacious controversialist, but in any personal discussion his humorous twinkle was disarming.’
    • ‘He knew she was only so pertinacious out of her love for him.’
    • ‘Well, I shall now offer a balanced view based on the facts before me: I find your attempts quite perspicacious and pertinacious, and wish you well accordingly.’
    determined, tenacious, persistent, persevering, assiduous, purposeful, resolute, dogged, indefatigable, insistent, single-minded, unrelenting, relentless, implacable, uncompromising, unyielding, tireless, unshakeable, importunate, stubborn, stubborn as a mule, mulish, obstinate, obdurate, strong-willed, headstrong, inflexible, unbending, intransigent, intractable, pig-headed, bull-headed, stiff-necked, with one's feet dug in, with one's toes dug in, wilful, refractory, contrary, perverse
    bloody-minded
    indurate
    View synonyms

Origin

Early 17th century: from Latin pertinax, pertinac- holding fast + -ous.

Pronunciation:

pertinacious

/ˌpəːtɪˈneɪʃəs/