of courseとは

語源

From literal meaning "of the ordinary course of events". The oldest attestation as "of course" is from the 1540s; the form "by course" (then spelled "bi cours") dates to about 1300.^[1]

副詞

of course (not comparable)

1. Used other than with a figurative or idiomatic meaning: see of,‎ course.

   This type of course does not suit me because the course is too expensive.

2. (idiomatic) Indicates enthusiastic agreement.

   Of course I'll go with you.

3. (idiomatic) Acknowledges the validity of the associated phrase.

   Synonyms: admittedly, confessedly

   Of course, there will be a few problems along the way.

   • 1907, Robert William Chambers, chapter IX, in The Younger Set (Project Gutenberg; EBook #14852), New York, N.Y.: D. Appleton & Company, published 1 February 2005 (Project Gutenberg version), OCLC 24962326:

     “Heavens!” exclaimed Nina, “the blue-stocking and the fogy!—and yours are pale blue, Eileen!—you’re about as self-conscious as Drina—slumping there with your hair tumbling à la Mérode! Oh, it's very picturesque, of course, but a straight spine and good grooming is better. […]”

4. (idiomatic) Asserts that the associated phrase should not be argued, particularly if it is obvious or there is no choice in the matter.

   Synonyms: naturally, indisputably

   Of course I know that!  You will, of course, surrender all your future rights to the property.

   • 1913, Joseph C. Lincoln, chapter 13, in Mr. Pratt's Patients:

     We tiptoed into the house, up the stairs and along the hall into the room where the Professor had been spending so much of his time. 'Twas locked, of course, but the Deacon man got a big bunch of keys out of his pocket and commenced to putter with the lock.

   • 2012, Christoper Zara, Tortured Artists: From Picasso and Monroe to Warhol and Winehouse, the Twisted Secrets of the World's Most Creative Minds, part 1, chapter 1, 25:

     There were other flapper-era starlets, of course—Louise Brooks, Greta Garbo—but they were poseurs by comparison.

   • 2013 June 22, “Snakes and ladders”, in The Economist, volume 407, number 8841, page 76:

     Risk is everywhere. From tabloid headlines insisting that coffee causes cancer (yesterday, of course, it cured it) to stern government warnings about alcohol and driving, the world is teeming with goblins. For each one there is a frighteningly precise measurement of just how likely it is to jump from the shadows and get you.

参考

• matter of course

参照