How to say "dependency" in Japanese

• 従属じゅうぞくCommon
  suru verb, intransitive verb, no-adjectiveThe abstract state of being subordinate or dependent on another power; a common word, and the choice when 'dependency' means dependence itself — as in one country's dependency on another — not a dependent territory.
  子供こどもは親おやに従属じゅうぞくしている。↗

  Children are subject to their parents' rules.
• 従属国じゅうぞくこく
  nounA country that is a dependency of another — the geopolitical sense; less common, but the most direct noun when you mean a dependent state rather than dependence itself.
• 付庸ふよう
  nounA dependent territory under another state's suzerainty — the 'vassal state' idea; less common, and for 'dependency' on its own it is seldom the word you reach for.
• 従国じゅうこく
  nounGlossed 'dependency; appanage', but marginal in practice: it names a dependent state or appanage, yet it is seldom the word you want — 従属国 is the safer choice for a dependent country.
• 属国ぞっこく
  nounPrimarily 'vassal state': a country under another's suzerainty; 'dependency' is a secondary gloss, so reach for it when the vassal nuance is what you mean, not dependence in general.

Use 従属 for 'dependency' as the state of dependence or subordination; the rest denote a dependent territory or state — 従属国 plainly, 属国 with a vassal-state nuance, 付庸 and 従国 only marginally.

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

• 従属じゅうぞくsubordination
• 従属国じゅうぞくこくdependency
• 付庸ふようdependency
• 従国じゅうこくdependency
• 属国ぞっこくvassal state
• 属領ぞくりょうpossession
• 依存関係いぞんかんけいdependence (relationship)
• 被保護国ひほごこくprotectorate (country)
• 隷属国れいぞくこくsubject nation
• 従属関係じゅうぞくかんけいsuperior-subordinate relation
• 係り受けかかりうけ(syntactic) dependency