Marmaduke

Possibly derived from the Old Irish name MÁEL MÁEDÓC. This name has been traditionally used in the Yorkshire area of Britain.

MáEL MáEDóC   male   Ancient Irish
Means "disciple of Saint MÁEDÓC" in Irish. Saint Máel Máedóc (also known as Malachy) was a 12th-century archbishop of Armagh.
MáEDóC   male   Ancient Irish
Meaning unknown. Saint Máedóc (also known as Áedán) of Ferns was a 7th-century Irish bishop.
OTHER FORMS
ANCIENT IRISH: Máedóc, Máel Máedóc
IRISH: Malachy