Solution

EVENT

3 clues

Happening

Word class: Common noun
Nature of clue: Synonym
Difficulty: Very easy

Other solutions to Happening

Occasion

Word class: Common noun
Nature of clue: Synonym
Difficulty: Very easy

Occurrence

Word class: Common noun
Nature of clue: Synonym
Difficulty: Easy

Other solutions to Occurrence

Words are categorized by artificial intelligence: there can be mistakes.