Title Reference: "Resurrection".
A resurrection is the process of giving life back to those who are dead. The procedures are many and different, depending on how the person died and if it was natural causes or homicide. Resurrection can be done on both individuals and a group. Resurrection is a big part of Jewish and Christian beliefs, and is mentioned several times throughout the Bible.
The title refers to Horatio being shot in the last season finale, and now he comes back... alive. Therefore, the expression that he came back after his death, is "resurrection".