guardian

Concise Oxford English Dictionary © 2008 Oxford University Press:
guardian/ˈɡɑːdiən/

▶noun

• 1 a defender, protector, or keeper.

• 2 a person legally responsible for someone unable to manage their own affairs, especially a child whose parents have died.

• 3 the superior of a Franciscan convent.

– derivatives
guardianship noun.

– origin ME: from OFr. garden, of Gmc origin; cf. ward and warden.