From Destiny 2 Wiki
Elimination is a PvP mode accessible from The Crucible.
Elimination is a 3v3 PvP mode that is available as a permanent standard gamemode. In this gamemode, rounds are only won when a team's players are all dead and unable to be revived.
Elimination is similar to Survival however, teams do not have a life pool to pull respawns from. Alternatively, you are allowed to revive downed allies after a short period of time, an infinite amount of times unless all members of your team are dead. A round is won after a team has no team members that are alive. Each round lasts for 1-minute and 30-seconds. First team to 5 rounds wins. If a tied round occurs, the round is reset and no team is awarded any points.