The phrase "major ass" is an informal way to describe something or someone as very strong, impressive, or extremely good at something. It emphasizes the intensity or significance of the subject.
Sentences with «major ass»
Just want to see my team kicking major ass again. (justarsenal.com)
The DTS kicks major ass as it had my walls shaking throughout the film. (jackasscritics.com)
I am very generous with my rating since I really want to kick major ass. (mediamikes.com)