How to say "decomposition" in Japanese

• 腐敗ふはいJLPT N1approx.Common
  noun, suru verb, intransitive verbDecomposition as putrefaction: organic matter such as food rotting and going bad. Use it for decay and spoilage rather than for a substance being broken down into its components.
  食品しょくひん包装ほうそうは腐敗ふはいを減へらす。↗

  Food packaging reduces spoilage.
• 腐乱ふらんCommon
  noun, suru verb, intransitive verbDecomposition as rotting; the word also means ulceration. Its rotting sense overlaps with 腐敗, and it is the one to use where decay and ulceration are both in view.
• 分解ぶんかいJLPT N2approx.Common
  noun, suru verb, transitive verb, intransitive verbDecomposition as a breaking down into components: chemical decomposition of a substance, disintegration, degradation. This is the scientific and technical sense, and it does not cover rotting or spoilage.
  水みずは酸素さんそと水素すいそに分解ぶんかいできる。↗

  Water can be decomposed into oxygen and hydrogen.

Choose 分解 for decomposition as a breaking down into components; choose 腐敗 for rotting or spoilage of organic matter; 腐乱 likewise denotes rotting and also covers ulceration.

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

• 腐敗ふはいdecomposition
• 腐乱ふらんdecomposition
• びらんsore
• 分解ぶんかいdecomposition