Son of the grey-haired one
A modern phonetic variant of the English surname Grayson. It traditionally denotes the son of a 'gray' or 'grey' haired man, or the son of a steward (from the Middle English 'greyve').
About 6 boys were named Greysun in 2025.
US births per 5-year period, 1990–present (SSA data).
