Translation guide
The English word "involution" has several distinct meanings, from mathematical self-application to biological shrinkage and social complexity. This guide focuses on the most common senses an English speaker might need to express in Japanese.
Express the mathematical concept of a function composed with itself, or an operation that is its own inverse.
Standard mathematical term for an involution, i.e., a function f such that f(f(x)) = x.
This mapping is an involution.
Loanword from English, used in some mathematical contexts, but less common than 対合.
Investigate the properties of the involution.
Describe the process by which an organ or tissue decreases in size, such as the uterus after childbirth or the thymus with age.
Medical term for involution, referring to the reduction in size of an organ or tissue.
Postpartum uterine involution is usually complete within six weeks.
General term for atrophy or shrinkage, can be used for involution in a broader sense, but 退縮 is more specific for natural involution.
Refer to the sociological phenomenon of 'involution' (neijuan), where people work harder but get less ahead due to hyper-competition.
Direct translation of the Chinese term 内卷, used in Japanese to describe the same social phenomenon of involution.
Involution is becoming more serious among young people in China.
Loanword used in discussions of the Chinese social concept, but 内巻き is more common in Japanese media.
The involution in this industry is abnormal.
Describe something that is complex, involved, or intricate, often in a literary or formal context.
The English word 'involution' in the sociological sense is a translation of Chinese 内卷. In Japanese, the direct loanword インボリューション is understood but 内巻き (うちまき) is more natural. Using 退縮 or 対合 would be incorrect in this context.
The thymus undergoes involution with age.