What is the meaning of the word "class"?

Definitions:

a body of students who are taught together noun
- early morning classes are always sleepy
a body of students who graduate together noun
- the class of '97
a collection of things sharing a common attribute noun
- there are two classes of detergents
a league ranked by quality noun
- They played ball in the bottom class for two years before moving up.
elegance in dress or behavior noun
- I have a lot of class.
people having the same social, economic, or educational status noun
- the working class
to arrange or order by classes or categories verb
- How would you class these pottery shardsare they prehistoric?