Fondness is love or affection for someone. Your fondness for your funny Spanish teacher might be part of what inspires you to work hard in his class.
When you have a fondness for a person, you feel warm or tender toward them. Your sister's fondness for young children probably makes her a great babysitter. You can also have a fondness for a thing: your friend's fondness for expensive shoes could cause her constant financial difficulty, and your fondness for cupcakes might influence you to learn how to bake.