Word: Pertinacious

The Word of the Day for Apr 13 is:
pertinacious \per-tuh-NAY-shuss\ adjective
HEAR IT
*1 a : adhering resolutely to an opinion or purpose b : perversely persistent
2 : stubbornly unyielding or tenacious

Example sentence:
The professor spent much of the class hour in debate with a pertinacious student about gun control.

Did you know?
If you say "pertinacious" out loud, it might sound familiar. That may be because if you take away the word's first syllable, you're left with something very similar to the word "tenacious," which means "tending to adhere or cling." The similarity between "pertinacious" and "tenacious" isn't mere coincidence; both words ultimately derive from "tenax," the Latin word for "tenacious," and ultimately from the verb "tenēre," meaning "to hold." But "pertinacious" and "tenacious" aren't completely interchangeable. Both can mean "persistent," but "pertinacious" suggests an annoying or irksome persistence, while the less critical "tenacious" implies strength in maintaining or adhering to something valued or habitual.

*Indicates the sense illustrated in the example sentence.
My sentence:
Maureen's pertinacious belief that Samuel had designs on her was vigoously denied by his girlfriend.