spiro

Spiron is a term with several related uses in science and culture. In chemistry, spiro denotes a class of compounds in which two or more rings are joined through a single shared atom, the spiro atom. The rings are arranged so that they share only that one atom, yielding a rigid, three-dimensional framework. These compounds are named with the spiro prefix, often written as spiro[n.m]alkane or spiro[n.m]heterocycle, where n and m indicate the sizes of the rings. An example is spiro[4.5]decane, consisting of two cyclohexane rings sharing one carbon. Spiro linkages influence properties such as rigidity, stereochemistry, and reactivity, and spiro architectures are explored in pharmaceuticals, materials science, and catalysis.

In onomastics, Spiro is a Greek masculine given name and surname. It is commonly a short form of Spyridon and is borne by individuals in Greek communities and the diaspora. The name appears in various fields, including politics, sports, and academia. A notable bearer is Spiro Theodore Agnew (1918–1996), who served as the 39th Vice President of the United States under President Richard Nixon from 1969 to 1973.

The root spiro- derives from the Greek speira meaning coil or spiral. As a prefix, it signals spiral or joint structures in science, appearing in terms such as spiro compounds, spirolactones, and related concepts. In popular culture, the term also appears in products and media, such as Spirograph, a drawing toy that creates circular and spiral designs.