In Grifball and SWAT the team with host almost always wins when latency is high. The term "sick host" describes such a situation. When one team can consistently kill players of the other team regardless of skill, but only because of having host and not experiencing lag, it is said that they have "sick host." "Sick" is colloquial modifier similar to 'awesome' which here greatly amplifies 'host.'
Whichever team has the player who has host does not necessarily win, but if a team has "sick host" there is no possible way for the opposing team to win. Playing a team with "sick host" is extremely frustrating and annoying because the game is never fair, and non-host players must suffer being "pwnd" for the duration of the game.
Red Team Teammate: "I know dude. He's got SICK HOST. Every time I run into that guy we both shoot at the same time but he always kills me."