a special anniversary of an event such as a sovereign's accession, esp a 25th, 50th, or 60th anniversary
a celebration of such an anniversary
(often Jubilee) a year of emancipation and restoration provided by ancient Hebrew law to be kept every 50 years
a period of time, proclaimed by the pope ordinarily every 25 years, during which a special indulgence (exemption from the penalties of sin) is granted to Catholics who perform certain works of repentance and piety
[early French jubilé from late Latin jubilaeus annus jubilee year, ultimatelyfrom Hebrew yōbhēl ram's horn, jubilee; the beginning of Jubilee year was announced by blowing ram's-horn trumpets]