English: mid feather
Welsh: adain ganol
Subject: Ystadau a Cadw
English definition: A thin piece of wood within the sash box, which keeps the two weights apart as they move up and down; also called a 'parting slip'. 
Welsh definition: Dernyn tenau o bren o fewn blwch y ffrâm, sy’n cadw pwysau’r ffenestr ar wahân wrth iddynt symud i fyny ac i lawr; fe’i gelwir hefyd yn ‘ddernyn gwahanu’.
Welsh context: Ffynhonnell: Taflen wybodaeth gyhoeddus Cyngor Gwynedd.