同(どう)〜

どう
prefix
same; similar; said
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 said 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 said person 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 was enacted in the said city.

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

COMMON COMPOUNDS (SAME):

  • 同時(どうじ) (same time; simultaneous)
  • 同僚(どうりょう) (colleague)
  • 同級生(どうきゅうせい) (classmate)
  • 同窓会(どうそうかい) (class reunion; alumni association)
  • 同意(どうい) (agreement; consent)
  • 同様(どうよう) (same; similar)
  • 同居(どうきょ) (living together)
  • 同情(どうじょう) (sympathy)

FORMAL/WRITTEN USE (THE SAID):

  • 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.

general
Added 2026.1.13 16:20 · Revised 2026.3.2 13:17
03500/03962_dou