Onomatopoeia + と + した = Adjective?


むっちりとした太股 was translated as “plump thighs”. Can I make an onomatopoeia into an
adjective by adding とした?




Short answer is no.

In most monolingual dictionaries, those onomatopoeias are noted explicitly as
such.

> [むっちり](https://kotobank.jp/word/%E3%82%80%E3%81%A3%E3%81%A1%E3%82%8A-641962)
>
> 1 〘副〙 **(多く「と」を伴って用いる)** ① 肌に張りがあって肉付きのよいさまを表わす語

* * *

Onomatopoeias describing sounds can rarely be used with とした - ザーザー(rain),
しとしと(rain)、ビュービュー(wind) won't work with と(した).

Those describing a state mostly work with とした - ニコニコ(smile), つるつる(polished or
slippery). But exceptions are not rare: カチカチとした (hard) doesn't work, it should
be カチカチの to modify a noun.

