an ‧ ni ‧ ver ‧ sa ‧ ry /ˌænəˈvɜːs ə ri, ˌænɪˈvɜːs ə ri $ -ɜːr-/ BrE AmE noun ( plural anniversaries ) [countable]
[ Date: 1200-1300 ; Language: Medieval Latin ; Origin: anniversarium , from Latin anniversarius 'returning each year' , from annus ( ⇨ ↑ annual 1 ) + vertere 'to turn' ]
a date on which something special or important happened in a previous year:
Jack and Kim celebrated their twentieth wedding anniversary in January.
anniversary of
A huge parade was held on the anniversary of the 1959 revolution.