course

• direction; part of a meal; series; layer; series of lessons or classes on a particular subject; unit of studies (especially on a university level)
hunt, pursue; run over; race
a course is a series of lessons or lectures.
a series of medical treatments is also called a course.
a course is also one part of a meal.
the course of a ship or aircraft is its route.
you can refer to the way that events develop as the course of history, nature, or events.
if a liquid courses somewhere, it flows quickly; a literary use.
see also golf course, racecourse.
you say of course when you are saying something that you expect other people to realize or understand.
you also use of course when you are talking about an event or situation that does not surprise you.
of course is also a polite way of giving permission or agreeing with someone.
you use of course to emphasize what you are saying.
a course of action is one of the things you can do in a situation.
if you do something as a matter of course, you do it as part of your normal work or way of life.
if something happens in the course of a period of time, it happens during that time.
if a ship or aircraft is on course, it is travelling along the correct route. if it is off course, it is no longer travelling along the correct route.
if something runs its course or takes its course, it develops naturally and comes to a natural end.