noun
pugnacity
pug-NAS-uh-tee/pʌɡˈnæsəti/
Readiness or eagerness to fight or argue.
The woman's repeated confrontations reveal pugnacity even toward a nonthreatening companion.

Etymology
The Latin adjective meant “combative” and came from a verb for fighting, especially with the fists. Pugnacity names that fighting disposition, extended to a readiness to argue.
More examples
- The boxer's pugnacity is obvious before the first bell.
- The lawyer's pugnacity makes settlement negotiations difficult.
- His pugnacity often gets him into fights at school.
Forms
pugnacious adjective — Eager to fight or argue.
Similar words
- combativeness
- Emphasizes a tendency to challenge or oppose other people.
- belligerence
- Emphasizes openly hostile behavior rather than readiness to fight.