'Diamond jubilee' definitions:

Definition of 'diamond jubilee'

(from WordNet)
noun
An anniversary celebrating the passage of 60 years

Definition of 'Diamond jubilee'

From: GCIDE
  • Diamond anniversary \Diamond anniversary\, Diamond jubilee \Diamond jubilee\, etc. an anniversary celebrated upon the completion of sixty, or, according to some, seventy-five, years from the beginning of the event commemorated. [Webster 1913 Suppl.]