Pertinacity
/ˌpɜːrtnˈæsəti/
Definition 1 of 1
Pro Tip 1/3Positive Connotation
Implies admiration for determination; often seen positively in academic or professional contexts. 
Her pertinacity in research earned her a prestigious award.
Pro Tip 2/3Not Stubbornness
'Pertinacity' is positive persistence, distinct from stubbornness, which is often seen as negative. 
Unlike his stubborn peers, his pertinacity was seen as a strength.
Pro Tip 3/3Formal Usage
Best used in formal or literary contexts, and may not be suitable for casual conversations. 
The scientist's pertinacity led to a breakthrough in the study.