According to Dictionary

dictionary.com:
a person attached to another by feelings of affection or personal regard.
a person who is on good terms with another;

American Heritage Dictionary :

1. A person whom one knows, likes, and trusts.
2. A person whom one knows; an acquaintance.
3. A person with whom one is allied in a struggle or cause; a comrade.
4. One who supports, sympathizes with, or patronizes a group, cause, or movement: friends of the clean air movement.

Oxford Dictionary
Person you like -> a person you know well and like who is not usually a member of your family