友人|ゆうじんyuujin[0]heiban (flat)

1. nounfriendmore formal than 友達
   私の友人ゆうじんの１人ひとりが私に会あいにきました。↗

   A friend of mine came to see me.

• Synonym友達ともだちNeutralThe everyday word, most common in speech. 「友人」 is more formal, typical of writing, formal settings, or introducing a friend to an elder.
• Synonym友ともWrittenAn elegant, concise written word, at home in prose and song lyrics, as in 「生涯の友」; also figurative for a constant companion, as in 「読書の友」.
• Synonym朋友ほうゆうWrittenA Chinese-style written word for friend or companion, rarely used in Japanese; in everyday speech say 「友人」 or 「友達」.
• SynonymフレンドCasualA loanword seen mostly in compounds and gaming or internet slang, as in 「フレンド申請」; seldom used alone to refer to a friend.
• Synonym仲間なかまNeutralCompanions who share an activity, as in 「仕事仲間」; the emphasis is on doing things together, not necessarily on close personal ties.
• Related仲良しなかよしCasualStresses a close, friendly bond; colloquial with a childlike feel, as in 「仲良しグループ」, while 「友人」 is a neutral label.
• Related同朋どうぼうWrittenMeans companions or fellows; also the historical title of the 「同朋衆」 who attended the shogun. Rare in modern usage.
• Related味方みかたNeutralA supporter or ally on your side, the opposite of 「敵」; 「友人」 is about personal friendship, 「味方」 about where someone stands.
• Related馴染みなじみNeutralA familiar relationship built up over time, as in 「幼馴染み」 or 「馴染みの店」; covers shops and regulars too, not just friends.
• Related友垣ともがきWrittenAn elegant word for congenial friends, found in songs, waka and other literature; not used in everyday speech.
• Related友朋ゆうほうWrittenA Chinese-style written word for trusted friends and fellows; rare in modern Japanese, where 「友人」 can be used instead.
• Related知友ちゆうWrittenA friend who knows you inside out, equivalent to 「親友」; a deeper bond than 「友人」, and a written-style word.

Use 「友人」 in formal situations and writing, 「友達」 in everyday speech. For partners in a shared activity pick 「仲間」, for allies on your side 「味方」, and for a bosom friend 「知友」. 「友」 is the elegant written choice, as in 「生涯の友」, while 「朋友」「同朋」「友垣」「友朋」 are literary rarities. Special uses: 「フレンド」 in games and online, 「馴染み」 for familiar places and faces, 「仲良し」 for close pals.

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

1. 友達ともだち。朋友ほうゆう。