A sugar daddy is a wealthy man who serves as a benefactor to a younger person. Typically, he bestows gifts to his beneficiary in exchange for companionship.
Sugar daddy recipients are usually younger females. In more extreme cases, the female receives gifts as a reward for sexual favors. In milder instances, the young woman simply provides friendship or accompaniment.
In the modern age of sugar daddies, the benefactor and beneficiary can be of any age or gender. The defining characteristic is that the sugar daddy dotes upon the "sugar baby" and spends freely on her.
A sugar daddy may also be defined as a wealthy male benefactor to a charity or other cause.