Event' The FIRST crossword solution for the term 'HISTORIC HAPPENING' is 'EVENT'. An EVENT is a significant occurrence, usually planned or organized, that has a particular purpose or significance. Events can range from small gatherings such as birthday parties to large-scale international conferences and festivals. Historic events are those that have had a lasting impact on society and are remembered in history books. Examples of historic events include the signing of the Declaration of Independence, the fall of the Berlin Wall, and the moon landing.