友・朋|ともtomo[1]atamadaka (head-high)

1. nounfriend; companion; comrade; pal
   まさかの時ときの友ともこそ真しんの友とも。↗

   A friend in need is a friend indeed.
2. nounaccompaniment; companion (e.g. book); complement; accessory

• Synonym友達ともだちNeutralThe most common word for friend, as in 「友達と遊ぶ」; 「友」 is more written and literary, and often appears in compounds.
• Synonym友人ゆうじんNeutralAlso means friend but more formal than 「友達」, used mainly in writing or polite contexts.
• Synonym朋友ほうゆうWrittenA written word for friend or companion; rare in modern usage, seen mostly in prose.
• SynonymフレンドNeutralA loanword, mostly in compounds or for friends in games and online, as in 「ボーイフレンド」.
• Synonym仲間なかまNeutralA companion you do things with, as in 「仕事仲間」; the bond is shared activity, not necessarily deep friendship.
• Related仲良しなかよしCasualColloquial, for someone you get along well with, as in 「仲良しグループ」; often used of children or close relationships.
• Related同朋どうぼうWrittenA written word for companion; it also refers to the monk-styled retainers who served the shogun. Rare today.
• Related味方みかたNeutralSomeone on your side, a supporter, as in 「いつも君の味方だ」; the emphasis is on allegiance, the opposite of 「敵」.
• Related馴染みなじみNeutralA familiar face or old acquaintance, as in 「幼馴染」 or 「馴染みの店」; the emphasis is on familiarity, not necessarily close friendship.
• Related友垣ともがきWrittenAn archaic, elegant word for a friend, seen mainly in songs and poetry.
• Related友朋ゆうほうWrittenA written word for friend, almost never used in modern Japanese.
• Related知友ちゆうWrittenA written word for a close, trusted friend; rare today, with 「親友」 the usual choice.
• Antonym敵てきNeutralRead 「かたき」, this means enemy or foe — the opposite of 「友」.
• Antonym仇あだNeutralThe same word as above: 「仇」 is simply another way of writing 「敵（かたき）」, not a separate antonym.

「友」 is the written, literary word for friend. In everyday speech say 「友達」, in formal or written contexts 「友人」. For people you work or act together with use 「仲間」, and for those on your side 「味方」; the opposite is 「敵」. The rest are literary rarities (「朋友」「同朋」「友垣」「友朋」「知友」) or special uses like 「フレンド」, 「馴染み」 and 「仲良し」.

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

1. （とも）自発的じはつてきに行動こうどうを共ともにしようとする、親族しんぞくもしくは配偶者はいぐうしゃ又または恋愛れんあい関係かんけいにある者もの以外いがいの人間関係にんげんかんけい。