mewn

Related to (either borrowed from or cognate with) Old Irish medón (“middle”).^[1]

• (standard, colloquial) IPA^(key): /mɛu̯n/
  • (North Wales, colloquial) IPA^(key): /mɨ̞u̯n/
  • (South Wales, colloquial) IPA^(key): /mɪu̯n/

mewn

1. in, at (indefinite nouns)

   Mae hi'n byw mewn tŷ mawr iawn.

   She lives in a very big house.

   Roedd y trên wedi stopio mewn gorsaf.

   The train had stopped at a station.

   Fyddwn ni ddim yna mewn pryd i weld y sioe.

   We will not be there in time to see the show.

• Mewn is used with indefinite nouns and other concepts; it should be regarded as the 'default' word for 'in'. Its equivalent for definite nouns is yn and is more restricted than mewn.

• i mewn (“inside; inwards”)
• i mewn i (“into”)
• o fewn (“within (distance, time period)”)
• mewn trefn (“in order, arranged”)
• tu fewn (“within, inside”)