affini

Affini is a term used in Italian with several related senses. As an adjective, affini is the plural form of affine, meaning related or akin, and it is used to describe similarities or kinship. In genealogy and law, affini also functions as a noun referring to relatives by affinity, that is, family members by marriage, such as in-laws. The feminine singular is affine, and the phrase “parenti affini” is commonly used in both masculine and feminine plural contexts.

Etymology traces affini to Latin affīnus, from affinis meaning near or related, a sense that passed into Italian and other Romance languages. The term has long been used to express relationships that are not purely blood-based but connected through marriage or other social ties.

In Italian usage, affini is frequently encountered in legal, genealogical, and social contexts to denote in-law relatives or kinship by affiliation. It can also appear in academic discussions about kinship networks, inheritance, or family arrangements where affinity is the relevant category of relation.

In mathematics and geometry, the cognate term affine is widely used, and the Italian equivalent trasformazione affine describes affine transformations—maps that take straight lines to straight lines and preserve parallelism, while not necessarily preserving distances or angles. The concept underpins affine geometry and is distinguished from more restrictive transformations like similarities or Euclidean motions.

Affini also exists as a surname in Italian-speaking areas, borne by individuals in various professions and public profiles. Overall, affini centers on notions of relatedness and connection, whether in social, legal, or mathematical contexts.