The phrase "big boss" refers to someone who holds a position of power and authority, and is in charge of a group of people or an organization. They are the leader or boss that has significant influence and control over others. Full definition
It was one of fast - paced hack and slash action with a healthy dose of big boss battles, quick time events and brutal, bloody combat. (attackofthefanboy.com)
Single player or co-op, it's a classic run and action game with big bosses that come with the style and challenges, wrapped up beautifully in 1930's style animation. (thisisxbox.com)
I always liked the solid snake more than big boss so this might be the best, epic, last solid snake appearing game in the series. (metacritic.com)