"Nos da" in Welsh means "goodnight." "You chi" is a polite form of "you" in Welsh, so "Nos da you chi" can be translated as "goodnight to you (polite/formal)."
Nos da, William.BTW the Welsh version of William is Gwilym.
nos da
IN welsh its "Bore da!" (said as "bor ed da")
Nos da
'Nos Da'
'Nos Da'
It depends which language the phrase is in. An aria is usually an operatic song. Nos da means goodnight in Welsh. In Portuguese the phrase means 'in the song'.
Nos da
Da is good. Nos da (Night good = Good night)
Nos da, but it literally means good night. Nos being night, da being good.
"Nos da, Tad"