Added 9 October 2026 rainfall /ˈɹeɪnfɔːl/ noun Categories: NatureUncommon Words noun ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about rainfall at Wordnik → Where our words come from → Water falling in drops from vapor condensed in the atmosphere. Origin From rain + fall. From Wiktionary, via Kaikki.org (CC BY-SA) Related Words: rainrainstormhailshowerrainsrainwaterrainingdownpourstormrainyprecipitationstormwater Back to today's word