adjective per·ti·na·cious \ˌpər-tə-ˈnā-shəs\

Definition of PERTINACIOUS

a :  adhering resolutely to an opinion, purpose, or design
b :  perversely persistent
:  stubbornly tenacious
per·ti·na·cious·ly adverb
per·ti·na·cious·ness noun
per·ti·nac·i·ty \-ˈna-sə-tē\ noun


  1. <a pertinacious little boy who was determined to catch and collect reptiles>
  2. <a pertinacious salesman who would simply not take No! for an answer>


Latin pertinac-, pertinax, from per- thoroughly + tenac-, tenax tenacious, from tenēre
First Known Use: 1626

Synonym Discussion of PERTINACIOUS

obstinate, dogged, stubborn, pertinacious, mulish mean fixed and unyielding in course or purpose. obstinate implies usually an unreasonable persistence <an obstinate proponent of conspiracy theories>. dogged suggests an admirable often tenacious and unwavering persistence <pursued the story with dogged perseverance>. stubborn implies sturdiness in resisting change which may or may not be admirable <a person too stubborn to admit error>. pertinacious suggests an annoying or irksome persistence <a pertinacious salesclerk refusing to take no for an answer>. mulish implies a thoroughly unreasonable obstinacy <a mulish determination to have his own way>.


Next Word in the Dictionary: pertinacyPrevious Word in the Dictionary: perthophyteAll Words Near: pertinacious
July 04, 2015
stringent Hear it
rigorous, strict, or severe
Take a 3-minute break and test your skills!
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears