Jubilee, Year of means in the bible: Every 50th anniversary year is given a name. The sound of a trumpet at the Day of Atonement announced the start of each year. This gave it its name. It was the only place where land had been transferred, other than in non-Levitical wallsed cities. All bondmen of Israelite descent were released Lev. 25:8-16, 23-55; 27:16-25. The Old Testament does not record any year of jubilee. However, the prophets make reference to it in several passages. Refer to Sabbatical Year.
(in Bible Dictionary)