退化(たいか)

たいか
noun, suru verb
degeneration; regression; atrophy
1. degeneration; regression; devolution
The biological process by which organs or functions become reduced or vestigial over generations.
使(つか)わない器官(きかん)は退化(たいか)する。
Organs that aren't used degenerate.
人間(にんげん)の尾(お)は退化(たいか)した器官(きかん)だ。
The human tailbone is a vestigial organ.
2. deterioration; decline; weakening
The process of becoming worse or less developed. Figurative regression.
運動(うんどう)しないと筋肉(きんにく)が退化(たいか)する。
Without exercise, muscles atrophy.

退化(たいか) is the opposite of 進化(しんか).

BIOLOGICAL TERMS:

  • 退化(たいか)器官(きかん): vestigial organ
  • 退化(たいか)する: to degenerate, to atrophy

FIGURATIVE USAGE:

  • 能力(のうりょく)の退化(たいか): deterioration of abilities
  • 機能(きのう)の退化(たいか): functional decline

EXAMPLES IN NATURE:

  • Whale pelvic bones
  • Blind cave fish eyes
  • Human wisdom teeth

Related Words

Antonym: 進化(しんか) (evolution)
general
Added 2026.1.17 6:25 · Revised 2026.1.19 21:17
06000/06030_taika