How to say "battalion" in Japanese

• 大隊だいたいCommon
  nounThe specific military unit, typically part of a regiment or brigade. This is the standard Japanese term for 'battalion' in contexts such as army organization, troop movements, and military history.
• 大部隊だいぶたい
  nounGlossed as 'battalion' but better understood as 'large force or large body of troops'. It is less common and emphasizes size rather than the formal unit; rarely the right choice for the precise sense of 'battalion'.
  それは五千ごせん人にんの兵員へいいんを擁ようする大だい部隊ぶたいなのです。↗

  That is a large force with 5,000 soldiers.

Use 大隊 for the military unit sense of 'battalion'; 大部隊 also appears in glosses but is less common and primarily means a large force rather than the specific unit.

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

• 大隊だいたいbattalion
• 大部隊だいぶたいbattalion