What does the last name Maynard mean?

Maynard is a surname of Anglo-Norman origin, derived from the Old French personal name Mainer, which in turn is derived from the Old German personal name Mainhard, composed of the elements magin ("strength", "power") and hard ("hardy", "brave", "strong"). The name was introduced to England by the Normans after the Norman conquest of 1066, and is first recorded in the Domesday Book of 1086.