Definition of the word: "Friends"

In about a week's time, exams will end and it also means that I will be entering another phase in my life...hope I can pass all my modules and graduate...This will also mean that the friends and acquaintances I have made through these 2 yrs in Aussie...It really made me curious what is actually the true meaning of friends and acquaintances...So I decided to flip through the dictionaries and here is the definitions:

Friends - A person whom one knows, likes, and trusts.
Acquaintances - Knowledge of a person acquired by a relationship less intimate than friendship

But during these 2 yrs, some people have made me found another definition for these 2 words...Here is my definition:

True friends - A person who will share the thicks and thins of your life.

Friends - A person whom will attend lectures, collect tutorial solutions on their behalf, ask you for help in their assignments, ask you questions only when exams are near, lend you things like cars when you need one...doing all these things without rejection...anything outside these, they will hide inside their cosy shell into the world of their own.

Acquaintances - A person who has outlived their usefulness and someone whom you will not keep in contact again.

Nonetheless, these 2 yrs I have known a few true friends who I would want to keep contact with in future...