先妻

1. Origins, structure, and basic meaning

• Structure: The written form is 先妻, read せんさい. Elements for previous and wife combine to denote a former or previous wife from an earlier marriage.
• Basic usage: 父の先妻 refers to the father’s former wife, while 祖父の先妻 refers to the grandfather’s wife from an earlier marriage.

2. Common pitfalls and similar expressions

• Not necessarily the first wife
  • The relationship is “former wife”; it does not necessarily specify that she was the first wife. Example: 小説の主人公は父の先妻が残した手紙を見つけた。 — The protagonist of the novel found a letter left by his father's former wife.
• A relationship in family records
  • In an old family register, the term distinguishes a person from a current marital relationship. Example: 古い戸籍には祖父の先妻の名も記されていた。 — The old family register also lists the name of my grandfather's former wife.