ju·bi·lee 
(jbə-lē′, j′bə-lē)
(jbə-lē′, j′bə-lē)n.
1.
a. A specially celebrated anniversary, especially a 50th anniversary.
b. The celebration of such an anniversary.
2. A season or occasion of joyful celebration.
3. Jubilation; rejoicing.
4. often Jubilee Bible In the Hebrew Scriptures, a year of rest to be observed by the Israelites every 50th year, during which slaves were to be set free, alienated property restored to the former owners, and the lands left untilled.
5. often Jubilee Roman Catholic Church A year during which plenary indulgence may be obtained by the performance of certain pious acts.
[Middle English jubile, from Old French, from Late Latin iūbilaeus, the Jewish year of jubilee, alteration (influenced by iūbilāre, to raise a shout of joy) of Greek iōbēlaios, from iōbēlos, from Hebrew yôbēl, ram, ram's horn, jubilee; see ybl in the Appendix of Semitic roots.]