Jousting is a raid technique used against named monsters that have very bad Area Effect (AE) attacks. It calls for the majority of the raid to stay outside of AE range until the AE goes off, then run in, do damage, and run back out before the next AE.
Timing is critical for this to work. The AE interval needs to be known, and one player, usually a raid-leader, needs to have a stopwatch and 2 macros (or some form of voice chat) to call AE incoming, all out! and AE done, all in! or words to that effect. Another method for AE timing is to use a parsing program which can automatically do this for the player (such as ACT. Only the MT stays nose to nose with the target throughout the encounter; even the MT healers will usually "joust out."