Meaning: The ending "-ist" shows that the word refers to "someone who does" something.
Example 1: A "biologist" is someone who studies life.
Example 2: A person who believes all war is bad is called a "pacifist". The root
"pac" means "peace".
Example 3: If someone belongs to a group that supports Communism, then he
or she would be called a "Communist".
Marxist - someone who believes in the philosophy of Karl Marx
scientist - someone who does science
specialist - someone who is an expert in one small area or has one special skill
optimist - someone who sees the bright side of life, the positive side
pessimist - someone who sees the darker side of life, the negative side
dentist - someone who fixes teeth
purist - someone who likes to keep things in their basic form, someone who rarely changes
realist - someone who faces reality directly
idealist - someone who believes in a better world, an "ideal" world