How to say "uncontrolled" in Japanese

• 意馬いば
  nounSuggests uncontrolled, unbridled impulse or desire, as if a horse bolted from its reins. It is less common, and you will rarely need it for everyday 'uncontrolled'; it appears mostly in set phrases like the idiom 意馬心猿.
• 無統制むとうせい
  na-adjective, nounCovers 'uncontrolled' in the sense of lacking overall regulation, organization, or control, such as uncontrolled growth or conduct. It is less common, and for most situations 野放図 is the word learners will actually hear and use.
• 野放図のほうずCommon
  na-adjective, nounThe common everyday choice: things left to run wild without restraint. It covers uncontrolled growth or spending that goes on endlessly, and rampant spread like weeds; it often carries a critical nuance.

For 'uncontrolled', 野放図 is the usual everyday choice; 意馬 and 無統制 are rarer alternatives, the former evoking unbridled impulse and the latter an overall lack of regulation or control.

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

• 意馬いばuncontrolled
• 無統制むとうせいuncontrolled
• 野放図のほうずendless (e.g. spending)