Dag \dag\ as a boy's name is pronounced dag. It is of Scandinavian origin, and the meaning of Dag is "daylight". Mythology: the son of Night who brought the daylight as he rode his horse around the earth. U.N. Secretary-General and Nobel Peace Prize winner Dag Hammarskj?
Dag has 4 variant forms: Daeg, Dagget, Daggett and Dagny.
For more information, see also the related name Dack.