[tuì huà]
become vestigial; degenerate; deteriorate; retrograde; devolution; retrogradation; retrogression; retroversion; regression; involution; degeneration; degenerescence; degeneracy; cataplasia; catagenesis; atresia
The wings of the chicken have become vestigial; it can no longer fly.
雞的翅膀逐漸退化， 不會在空中飛行了。
After a few years' planting, the quality of the potato crop deteriorates.
土豆種了幾年之后就會退化。