Ténacité.
Persistent determination; SYN. perseverence, persistence, persistency, tenacity, tenaciousness, pertinacity.
1. A fixedness in will, opinion, or resolution that can not be shaken at all, or only with great difficulty; firm and usually unreasonable adherence to an opinion, purpose, or system; unyielding disposition.
2. The quality or state of being difficult to remedy, relieve, or subdue
ETYM French persévérance, Latin perseverantia.
The act of persevering; SYN. persistence, perseveration.