純|じゅんjun[1]atamadaka (head-high)

1. na-adjective, taru-adjective, adverb (with と)innocent; chaste; naive
2. prefixpure; unmixed; genuine; unalloyed

• Synonym純粋じゅんすいNeutralThe most common word for 'pure'—free of impurities or pure-hearted. 「純」 is a literary single character, mostly a prefix or used of a person's simple innocence.
• Synonym純朴じゅんぼくWrittenWritten word for an unsophisticated, unaffected character; describes a person's personality. 「純」 stresses simplicity with no ulterior thoughts.
• Synonym無垢むくWrittenWritten word for spotless purity, or for pure, unadulterated material. 「純」 is about a person's simple, honest character.
• SynonymピュアCasualColloquial loanword meaning pure and clean, or fresh and innocent. 「純」 is a one-kanji word of Sino-Japanese origin.
• Synonym純情じゅんじょうNeutralA pure, innocent heart, often in romantic contexts. 「純」 is broader in scope.
• Synonym純真じゅんしんNeutralPure and innocent, free of guile. 「純」 is more concise and literary.
• Synonym無邪気むじゃきNeutralInnocent and free of malice, often said of children. 「純」 leans toward simple, unspoiled character.
• Synonym清純せいじゅんWrittenWritten word for fresh, pure innocence, often of young girls. 「純」 is broader.
• Synonym純潔じゅんけつWrittenWritten word for purity and chastity. 「純」 leans toward simple, unspoiled character.
• SynonymすれてないCasualColloquial: not yet jaded by the world, still simple in outlook. 「純」 stresses an innately pure nature.
• SynonymイノセントCasualColloquial loanword: innocent in the sense of guiltless, or naive. 「純」 leans toward simple character.
• Synonym天真てんしんWrittenWritten word for natural, unaffected simplicity. 「純」 leans toward simple, unspoiled character.
• Synonym天真爛漫てんしんらんまんWrittenWritten four-character word for open, artless innocence. 「純」 is more concise.
• Related初々しいういういしいNeutralFor the fresh, green innocence of the young, as in 「初々しい新入社員」. 「純」 stresses an innately pure nature.
• Related清いきよいNeutralClear and pure, physically or morally, as in 「清い心」. 「純」 stresses simple, unspoiled character.
• Related純一無雑じゅんいつむざつWrittenWritten four-character word for pure and unadulterated, in heart or substance. 「純」 is more concise.
• Related無雑むざつWrittenWritten word for pure and unmixed. 「純」 is the more common choice.
• Antonym不純ふじゅんNeutralAntonym: impure or adulterated, or with impure motives, as in 「不純な動機」. The direct opposite of 「純」.

Use 「純」 in writing for a person of simple, pure character or as a prefix in 「純〜」 words, as in 「純な心」 and 「純利益」. For plain 'pure, unmixed' pick 「純粋」, the everyday default; for pure-hearted innocence 「純真」; for childlike naivety 「無邪気」; for fresh purity, esp. of young girls, 「清純」. 「純朴」「無垢」「清い」 and the rest each stress a particular shade—unsophisticated, spotless, clear—and 「不純」 is the antonym.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. （ジュン）人柄ひとがらが素直すなおで無垢むくなさま。純情じゅんじょう。