Thanks. It does appear to be a family name. However, this record is the only instance of "Dujon" in church records from the church of New Amsterdam (later known as the city of New York). It's not in other records that are believed to be for these same people, and I've not found it in other New Netherland churches (but I have not checked records of every church; there is no single consolidated database).
Is this a family name known from the Netherlands (or Flanders, or Friesland, etc.)? The child's father and grandfather are supposedly from Wageningen, Gelderland, or Beest, Gelderland.