professor
- teacher
‘professor’
In a British university, a professor is the most senior teacher in a department.
Professor Cole is giving a lecture today.
She was professor of English at Strathclyde University.
In an American or Canadian university or college, a professor is a senior teacher. He or she is not necessarily the most senior teacher in a department.
He's a physics professor at Harvard.
My professor allowed me to retake the test.
‘teacher’
Don't use ‘professor’ to refer to a person who teaches at a school or similar institution. Use teacher.
I'm a qualified French teacher.
The teacher set us some homework.