pugnacity (n.)

"disposition to fight, quarrelsomeness," c. 1600, from Latin pugnacitas "fondness for fighting," from pugnax (genitive pugnacis) "combative," from pugnare "to fight," especially with the fists, "contend against," from pugnus "a fist" (from PIE *pung-, nasalized form of root *peuk- "to prick").