IPA: /ˈreɪnaʊt/
KK: /ˈreɪnˌaʊt/
An event that has been canceled or postponed due to rain, especially in sports or outdoor activities.
The baseball game was a rainout, so we will have to reschedule it for next week.
Rainout → The word is formed from "rain" (from Old English "regn", meaning water droplets falling from the sky) and "out" (meaning outside or away). The term "rainout" refers to an event, such as a game, being canceled due to rain, indicating that the rain has affected the situation outside.
Think of rain falling from the sky ('rain') and affecting something happening outside ('out') — that's why a rainout means an event canceled due to rain.
No commonly confused words.