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.'
Less common today
Dillian isn't in the latest US Top 1000. It last peaked at #1,978 in 1992.
British professional heavyweight boxer
US births per 5-year period, 1990βpresent (SSA data).