How can I express "a particular/a certain" thing?


I am studying vocabulary and I came across the word
[然る](https://jisho.org/word/%E7%84%B6%E3%82%8B), either read as さる or しかる
(usually written in Kana) and means "A Particular/A Certain" noun. However,
there was only one example sentence on there and it wasn't marked as a Common
Word, which seems to be a red flag for me in terms of learning the correct
vocabulary.

How can I use さる／しかる to express "a particular/a certain" thing? Secondly, is
there a better or more natural way to express this phrase?

Example idea:

> 卒業するように、さる授業を取らなければいけません。  
>  In order to graduate, you must take a certain class.




It's always read as さる when it means "a certain ～". You can think of it
basically as a literary version of [ある meaning "a certain ～" or "one
～"](https://japanese.stackexchange.com/q/50257/5010). In relatively casual
situations, さる sounds more or less "serious", and it sometimes has a nuance of
"don't pry into this".

  * ある授業を取らないといけません → sounds natural and neutral
  * さる授業を取らないといけません → uncommon; may sound like this class is somehow special/problematic when used in a casual blog article or such
  * ある会社 → neutral
  * さる会社 → maybe the speaker does not want to disclose the name of the company




It's always read as さる when it means "a certain ～". You can think of it
basically as a literary version of [ある meaning "a certain ～" or "one
～"](https://japanese.stackexchange.com/q/50257/5010). In relatively casual
situations, さる sounds more or less "serious", and it sometimes has a nuance of
"don't pry into this".

  * ある授業を取らないといけません → sounds natural and neutral
  * さる授業を取らないといけません → uncommon; may sound like this class is somehow special/problematic when used in a casual blog article or such
  * ある会社 → neutral
  * さる会社 → maybe the speaker does not want to disclose the name of the company

