One who, or that which, defends or shields from injury, evil, oppression, etc.; a defender; a guardian; a patron.
One having the care of the kingdom during the king's minority; a regent.
A cardinal, from one of the more considerable Roman Catholic nations, who looks after the interests of his people at Rome; also, a cardinal who has the same relation to a college, religious order, etc.
I come here tonight as a sister, blessed with a brother who is my mentor, my protector and my lifelong friend. And I come here as a wife who loves my husband and believes he will be an extraordinary president. Michelle Obama