(adj.) eager to fight
combative, aggressive, antagonistic, belligerent, bellicose, warlike, quarrelsome, argumentative, contentious, disputatious, hostile, threatening, truculent.
The boy's pugnacious behavior causes him to get any many fights with people.
The man is very pugnacious therefore people prefer to stay out of his way.
Tattooed bully acts tough and gets knocked out in 20 seconds!(Official)