pertinacious

[ pur-tn-ey-shuhs ]
/ ˌpɜr tnˈeɪ ʃəs /

adjective

holding tenaciously to a purpose, course of action, or opinion; resolute.
stubborn or obstinate.
extremely or objectionably persistent: a pertinacious salesman from whom I could not escape.

Origin of pertinacious

First recorded in 1620–30; pertinaci(ty) + -ous

OTHER WORDS FROM pertinacious

per·ti·na·cious·ly, adverb per·ti·na·cious·ness, noun

Example sentences from the Web for pertinaciously

British Dictionary definitions for pertinaciously

pertinacious
/ (ˌpɜːtɪˈneɪʃəs) /

adjective

doggedly resolute in purpose or belief; unyielding
stubbornly persistent

Derived forms of pertinacious

pertinaciously, adverb pertinacity (ˌpɜːtɪˈnæsɪtɪ) or pertinaciousness, noun

Word Origin for pertinacious

C17: from Latin pertināx, from per- (intensive) + tenāx clinging, from tenēre to hold