Frag out means getting a bunch of kills.

What does fragging out mean in gaming?

The definition of fragging from the dictionary is: deliberately kill (an unpopular senior officer), typically with a hand grenade. In today's shooter games we see the term frags being thrown out a lot.

Why do they call it fragging?

The origins of the word come from the Vietnam War by U.S. soldiers. The term “fragging” was used to explain intentional attempts to kill a fellow soldier. The word was used because oftentimes a frag grenade was the weapon used in “fragging” incidents.