An anniversary is a special occasion that marks the passing of a certain amount of time since an event occurred. The term 'anniversary 50th' specifically refers to the 50th anniversary of an event. The crossword solutions for this term are 'GOLDEN' (6 letters), 'JUBILEE' (7 letters), and 'MILESTONE' (9 letters). These words all refer to the significance of the 50th anniversary, with 'GOLDEN' referring to the preciousness of the event, 'JUBILEE' referring to the celebration of the event, and 'MILESTONE' referring to the importance of the event.