unwaith

un (“one”) +‎ gwaith f (“time”)

• (North Wales) IPA^(key): (standard) /ˈɨ̞nwai̯θ/, (colloquial) /ˈɨ̞nwɛθ/
• (South Wales) IPA^(key): (standard) /ˈɪnwai̯θ/, (colloquial) /ˈɪnwɛθ/

unwaith

1. once
2. (used at the beginnings of fairytales) once upon a time

• ar unwaith (“at once”)
• unwaith eto, eto unwaith (“once again”)
• unwaith yn y pedwar amser (“once in a blue moon”)