I've noticed a lot of people are assholes, and give biased definitions saying it either "r0xxorzez all t3h othar games!!11!!1!111" or "is a total fag noob shitty game" This is an unbiased definition of HALO: Combat evolved:
1:n.A first-person-shooter game for the Microsoft X-box in which the main protagonist Master Chief and his A.I. guide Cortana fight through a giant alien construct (the halo) in space alongside marines to destroy it before it eradictes all life in the universe. To further complicate things, the Covenant, a hierarchy of aliens bent on killing humans because they are believed to be inferior, have landed on the ring and believe it to be a sacred artifact, so they naturally try to defend it. Also, a parasitic plague known as the flood have been contained on the ring, and are released by the covenant. An evil and unsatiable appetite for sentient flesh drives the flood to infect and destroy all biological matter in the universe, and the Master Chief must get through them too to destroy the ring (which leads to a couple of the most annoying levels ever in game history). Halo and it's successor, HALO 2, have active online communities, as they both sport a form of online play.
2.adj.High Altitude Low Opening jump from a plane
1) Halo is an addictive fps (In my own opinion) for the Xbox. Many people say it's "linear" "repetitive" "slow" or "has crappy graphics", or that "people who think halo rules don't play fps games". I love halo, along with games like: Half-life (1 and 2), Far-Cry, The Medal of Honor and Call of Duty series, and Resistence: Fall of Man to name a few. Furthermore, people are too hooked on free-roam games with gorgeous graphics, without it occurring to them that maybe if a game has good gameplay (which i personally believe it does), then it really doesn't matter. God of War has linear gameplay with somewhat repetitive enemies, but the gameplay is so good you overlook that. People need to think more.
2. Alpha team made a HALO jump from the plane