what does noun +とする mean?


I'm aware of some of the meanings of とする but in this sentence

> 聞きおわると、彼は愕然としていた。

愕然 is apperently a noun that has something to do with feelings **astonishment
/ shock etc**

and one of the definitions of とする states that it has the meaning of to feel
(e.g. after sound symbolism or psychological experience word)/to look/to feel
like.

I don't quite understand the definition but i've just assumed that とする is used
to express feelings but i can't find any examples other than with 愕然. In fact
when i look for sentences with 愕然 they all have とする attached and i don't
understand whether it's exclusively used with this noun or are there other
examples.




Here are some similar phrases in the order they came up in my mind.

  * 戦々恐々【せんせんきょうきょう】とする
  * 嬉々【きき】とする (eg 嬉々として話す)
  * のんびりとする (also written as のんびりする)
  * 堂々【どうどう】とする
  * 悄然【しょうぜん】とする
  * 恍惚【こうこつ】とする (eg 恍惚とした表情)
  * 憮然【ぶぜん】とする (eg 憮然とした表情)
  * 凜【りん】とする (eg 凜とした表情)
  * ゆっくりとする (also written as ゆっくりする)
  * こそこそとする (also written as こそこそする)
  * 飄々【ひょうひょう】とする (eg 飄々とした態度)

Please consult your favorite dictionary for the meanings because I really
don't know how to translate many of these words naturally into English :)

Among these, のんびりと, ゆっくりと and こそこそと seem to belong to a difference category
because と is optional and they can work as standalone adverbs which directly
modify a verb without する (eg, ゆっくり(と)過ごす, のんびり(と)考える). 堂々と also works as a
standalone adverb for whatever reason (eg, 堂々と語る). None of the words in the
list works as a na-adjective.

For other (fairly difficult) kanji words, they are usually followed by
～とする/～として/～とした, and と cannot be omitted. And yes, they are all related to
emotions and/or facial expressions.




Here are some similar phrases in the order they came up in my mind.

  * 戦々恐々【せんせんきょうきょう】とする
  * 嬉々【きき】とする (eg 嬉々として話す)
  * のんびりとする (also written as のんびりする)
  * 堂々【どうどう】とする
  * 悄然【しょうぜん】とする
  * 恍惚【こうこつ】とする (eg 恍惚とした表情)
  * 憮然【ぶぜん】とする (eg 憮然とした表情)
  * 凜【りん】とする (eg 凜とした表情)
  * ゆっくりとする (also written as ゆっくりする)
  * こそこそとする (also written as こそこそする)
  * 飄々【ひょうひょう】とする (eg 飄々とした態度)

Please consult your favorite dictionary for the meanings because I really
don't know how to translate many of these words naturally into English :)

Among these, のんびりと, ゆっくりと and こそこそと seem to belong to a difference category
because と is optional and they can work as standalone adverbs which directly
modify a verb without する (eg, ゆっくり(と)過ごす, のんびり(と)考える). 堂々と also works as a
standalone adverb for whatever reason (eg, 堂々と語る). None of the words in the
list works as a na-adjective.

For other (fairly difficult) kanji words, they are usually followed by
～とする/～として/～とした, and と cannot be omitted. And yes, they are all related to
emotions and/or facial expressions.

