First occurrence
Unusual event and first occurrence are semantically related. In some cases you can use "Unusual event" instead a noun phrase "First occurrence".
Unusual event
First occurrence and unusual event are semantically related. You can use "First occurrence" instead a noun phrase "Unusual event".
Mutual synonyms
Cite this Source
Unusual event and First occurrence. (2016). Retrieved 2026, July 30, from https://thesaurus.plus/related/first_occurrence/unusual_event
First occurrence & Unusual event. N.p., 2016. Web. 30 Jul. 2026. <https://thesaurus.plus/related/first_occurrence/unusual_event>.
Unusual event or First occurrence. 2016. Accessed July 30, 2026. https://thesaurus.plus/related/first_occurrence/unusual_event.
Google Ngram Viewer shows how "first occurrence" and "unusual event" have occurred on timeline