Son of the sea or faithful
Dillian is a rare name with dual potential roots. It is most frequently used as a variant of the Welsh name Dylan, meaning 'son of the sea,' or as a variant of the French and English name Dillon, which can mean 'faithful' or 'loyal.'
Fewer than 5 boys were named Dillian in 2025.
US births per 5-year period, 1990–present (SSA data).
British professional heavyweight boxer
