退化

たいか

degeneration, retrogression

JLPT N1

Character Breakdown

Meaning and Usage

"退化" (たいか) means degeneration or retrogression, often used to describe a decline in function, ability, or condition. It is common in scientific contexts such as biology, technology, and psychology.

Common Contexts

You will often see "退化" used when talking about biological evolution (退化 of species or organs), deterioration of machines or skills, and sometimes in social or cultural decline.

Collocations and Patterns

  • 退化する: to degenerate or deteriorate
  • 退化した機能: degenerated function
  • 退化を防ぐ: to prevent degeneration

Register and Nuance

"退化" is a formal term, mostly used in written or academic contexts. In casual conversation, people might use simpler words like "悪くなる" (to get worse).

Common Mistakes

Learners sometimes confuse "退化" with "進化" (しんか, evolution). Remember that "退化" implies a backward or negative change, while "進化" means positive development or evolution.

Example Sentences

このきかいはふるくなってせいのうがたいかした。

This machine has become old and its performance has degenerated.

せいぶつのしんかとたいかはしぜんのせつりだ。

Evolution and degeneration of organisms are laws of nature.

げんごのうりょくがたいかしないようにまいにちべんきょうしている。

I study every day so that my language ability does not degenerate.