What does odst stand for in halo3

In Halo 3, ODST are Orbital Drop Shock Troopers. Other terms in or associated with Halo- UNSC- United Nations Space Command. MJOLNIR- Mark armor used by the Spartans. HUD- Heads up display. NoS- No Scope 4 Shot- Killing someone with the Battle Rifle with the fewest possible shots. BK- Bad Kid- A player who typically brags about their level of skill and turns out to be inexperienced.