Translation guide
The process of becoming worse in quality, condition, or value. In Japanese, this concept is expressed through various nouns and verbs depending on what is deteriorating and the context.
Expressing that something is getting worse in quality or condition over time.
The most common and general term for deterioration or worsening of a situation, condition, or quality. Used for health, relationships, weather, economy, etc.
His condition deteriorated.
The relationship is only getting worse.
Refers to deterioration in quality, especially of materials, products, or abilities. Often implies degradation or loss of original properties.
Plastic deteriorates from UV rays.
The battery degrades quickly.
A drop or decline in level, standard, or ability. Often used for performance, quality, or function.
The quality is deteriorating.
My concentration declined.
Describing the physical breakdown of objects, structures, or materials over time.
Deterioration due to aging, especially for buildings, infrastructure, or equipment. Implies becoming old and worn out.
The deterioration of the bridge is a problem.
Corrosion or decay, often chemical or biological. Used for metals rusting, wood rotting, etc.
Wear and tear from friction. Used for mechanical parts, tires, etc.
Referring to the worsening of moral standards, culture, or society.
Specifically about worsening health or medical conditions.
悪化 (あっか) is the most general 'worsening' and can be used for almost any negative change. 劣化 (れっか) specifically means degradation in quality or performance, often of materials or skills. 低下 (ていか) is a decline or drop in level, often used for measurable things like quality, ability, or temperature.
The pipe corrosion is progressing.
The tire wear is severe.
He fell into depravity through drinking and gambling.
体力の衰えを感じる。
I feel a decline in my physical strength.