同(どう)〜

どう
prefix
same; similar; the aforementioned
formal
1. same; identical
Prefix indicating sameness or identity.
同僚(どうりょう)と昼食(ちゅうしょく)を食(た)べた。
I had lunch with a colleague.
同(どう) + 僚(りょう) = colleague (same work)
同時(どうじ)に二(ふた)つのことはできない。
I can't do two things at the same time.
同(どう) + 時(じ) = same time
同年代(どうねんだい)の友人(ゆうじん)が多(おお)い。
I have many friends of the same generation.
2. the said; the aforementioned
Used in formal writing to refer back to something mentioned.
同社(どうしゃ)は来年(らいねん)新製品(しんせいひん)を発売(はつばい)する。
The company will release a new product next year.
同(どう) + 社(しゃ) = the same/said company
同氏(どうし)は明日(あした)来日(らいにち)する予定(よてい)だ。
The person in question is scheduled to arrive in Japan tomorrow.
同市(どうし)では新(あたら)しい条例(じょうれい)が施行(しこう)された。
A new ordinance has taken effect in the city.

同(どう)〜 is a prefix meaning 'same' or 'the said.'

Compounds (SAME)

COMPOUNDS (formal writing):

  • 同社(どうしゃ) (the said company)
  • 同氏(どうし) (the said person)
  • 同日(どうじつ) (the same day; that day)

This usage appears frequently in news articles and formal writing.

Related Words

Related: 同(おな)じ (same (adjective))
general
Added 2026.1.13 16:20 · Revised 2026.10.12 4:28
03500/03962_dou