Son of the gray-haired one
A modern American variant of the English surname Grayson. It traditionally denotes the son of a 'reeve' (a steward or local official) or simply the son of a man with gray hair.
Less common today
Greysen isn't in the latest US Top 1000. It last peaked at #956 in 2017.
US births per 5-year period, 1990–present (SSA data).
