純じゅん一いつ無む雑ざつ

Meanings

noun, na-adjective, noun which may take the genitive case particle 'no'

pure and unadulterated; pure in heart; simplehearted

A yojijukugo describing something completely pure, without mixture or impurity; can refer to substances, character, or motives. Literary and somewhat formal.

彼かれの純じゅん一いつ無む雑ざつな信しん仰こう心しんは多おおくの人ひとを感かん動どうさせた。
His pure and unadulterated faith moved many people.
この水みずは純じゅん一いつ無む雑ざつで、一いっ切さいの不ふ純じゅん物ぶつを含ふくまない。
This water is pure and unadulterated, containing no impurities whatsoever.

Kanji

純genuine, purity, innocence
一one, one radical (no.1)
無nothingness, none, ain't
雑miscellaneous

Related words

純じゅん粋すい
純粋 is the common word for 'pure' in everyday contexts. 純一無雑 is a more emphatic, literary yojijukugo emphasizing absolute purity without any mixture.
純じゅん真しん
純真 means 'pure and innocent', often used for a person's heart or character. 純一無雑 can also describe purity of heart but with a stronger nuance of being untainted by any foreign element.

Built from

純じゅん一いつ+無む雑ざつ

Etymology

A yojijukugo composed of 純 (pure), 一 (one, single), 無 (without), and 雑 (miscellaneous, impurity). The combination literally means 'pure, single, without mixture', emphasizing absolute purity. The exact historical origin is uncertain, but it follows a common pattern of four-character idiomatic compounds in literary Chinese and Japanese.