姻族

1. Origins, structure, and basic meaning

• Structure: 姻族 (いんぞく) means relatives connected through marriage. 姻族も expands an invitation; 姻族関係 names a relationship type in a family tree.
• Basic usage: In-laws as well as blood relatives attend an event; marriage relationships are checked in an old genealogy.

2. Common pitfalls and similar expressions

• In-laws included among guests and marital links in a genealogy
  • Pairing with 親族だけでなく distinguishes relatives by marriage from blood kin. Adding 関係 shifts focus from people to the network of relations.