Fourmer

Fourmer is an informal term used across several disciplines to denote a molecule, polymer, or assembly that consists of four repeating or component units. The word is constructed from four and the suffix -mer, following the pattern of other designations such as dimer, trimer, and tetramer. Because it is informal, its exact meaning and usage can vary by context.

In chemistry and materials science, a fourmer typically refers to a four-unit oligomer in which four monomer units are linked together. In this sense, fourmer is largely synonymous with tetramer or a short four-unit chain, though formal nomenclature often prefers tetramer for specific implications about structure or function.

In biochemistry and structural biology, assemblies with four subunits are commonly described as tetramers. While tetramer is the standard term in formal scientific writing, fourmer may appear in less formal or introductory contexts to emphasize the four-subunit nature of the complex.

In computational linguistics and information theory, four-mer can denote a four-character sequence, also known as a quadgram. Such four-letter or four-symbol sequences are used in character-level models, motif discovery, and various analyses of text data.

Overall, fourmer serves as a flexible, informal label for any entity comprising four units. In formal discourse, the term is often replaced by tetramer, four-mer oligomer, or quadgram, depending on the field and the specific nature of the four-unit composition.