授業- is it the class or class-time or more broadly?


<http://kotobank.jp/word/%E6%8E%88%E6%A5%AD>

list this word in one line so it doesn't seems like it should have lots of
nuances.

Here some usage in my textbook. 出席 してこそ、授業の意味があるのです。

implies a sum of knowledge passed in class time.

授業が終わるか終わらないかのうちに、彼は教室を出た。

implies class-time.

Is 授業 really defined so broadly? What are the its limits of meaning and how to
discrimate in practice? www.jisho.org lists 授業時間 as class-time, are there
correct term for scheduled class-time and actual class-time? I know from my
time as an ALT in a Japanese high-school, these are certainly not the same
periods of time.




授業 is defined in 大辞林 as 「学校などで，学問などを教えること。」

A translation of this would be "teaching a discipline/science at a school or
the like." So perhaps it would be best defined as "instruction", "teaching".
An instance of teaching/instruction would be a "lecture", "class", or
"lesson".

Its uses:

  * As a verb: 授業する to give a lecture, to instruct
  * As a noun: 授業 teaching (at a school), a lecture, a lesson

Common phrases:

  * (...の)授業を受ける receive a lesson (in ...), attend a lecture (on ...)
  * 授業を取る take a class (i.e. choosing it for the semester)
  * 授業に参加する attend a class, participate in a class
  * 授業が終わったら once class ends, after class is over, after classes




My take. 授業 is simply **class** (or its synonyms 'course','lesson', etc.) I
don't think it has any inherent time aspect. At least, not anymore than
'class' has in English. I'm not sure what the translation is in your book, but
to me 出席してこそ、授業の意味があるのです means 'class is given meaning by attending it' (very
loosely). If you take a first-person stance the sentence would change. Depends
on context.

授業時間 could mean either 'time in class', or 'class hours'. Again, context.
Examples:

授業時間を減らす cut back on classroom time

通常の授業時間は9時から5時までです。 Course hours are usually from 9am to 5pm.

I believe if you want to be specific about 'actual' class time/'scheduled'
class time. You need to add more descriptors (just like in English, actually).
Like, 予定 for 'scheduled'. For 'actual', probably 実際の. I'm not sure if you can
say 実時間 here, a native speaker could probably confirm that.

Sorry I couldn't be more help.

