Old Irish in

← Proto-Celtic *sindos (inherited)

← Welsh yn (cognate)

← Proto-Indo-European *sḗm (inherited)

← Proto-Indo-European *só (mention)

← Latin (mention)

← Old Irish sin (mention)

← Old Irish int (link)

← Old Irish insin (link)

← Old Irish inso (link)

← Old Irish duús in (link)

← Old Irish [[cach]], [[cech]] (mention)

← Old Irish for (mention)

← Middle Welsh - (cognate)

→ Irish an (inherited)

→ Irish an (inherited)

→ Irish inniu (mention)

→ Scottish Gaelic an (inherited)

→ Scottish Gaelic an-diugh (mention)

→ Manx yn (inherited)

→ Old Irish sin (mention)

→ Old Irish sund (mention)

→ Old Irish indiu (mention)

→ Old Irish inso (compound)

→ Old Irish inunn (mention)