common-law couple; couple in an illicit union
Refers to a couple living together as if married without legal registration, often with a nuance of an improper or secret relationship. The term can carry a slightly old-fashioned or judgmental tone.
They have been living together as a common-law couple for over ten years.
In the past, couples in illicit unions were looked down upon by society.
内縁 is a more neutral, legal term for a de facto marriage, while 馴れ合い夫婦 often implies an improper or secret relationship.
同棲 simply means cohabitation without the marital implication, and is more commonly used in modern contexts.
Standard kanji spelling.
Mixed kana-kanji spelling; the first part is written in kana.
Compound of 馴れ合い (nareai, 'collusion, secret understanding') and 夫婦 (fūfu, 'married couple'). The exact historical derivation is uncertain, but the term suggests a couple whose relationship is based on an informal, possibly improper, agreement rather than formal marriage.