Origin: Latin suffix -ous
Pugnacious has 3 different meanings across 1 category:
tough and callous by virtue of experience
ready and able to resort to force or violence
"pugnacious spirits...lamented that there was so little prospect of an exhilarating disturbance"
"they were rough and determined fighting men"
Naturally aggressive or hostile; combative; belligerent; bellicose.
The word comes from the Latin stem pugnāx, which is derived from pugnō meaning "to fight." This root ultimately traces back to pugnus, the Latin word for "fist."