analoges

Analogues, or analogs, is a term used across disciplines to describe entities that resemble a reference item in structure, function, or purpose, without being identical. The plural form analogues is common in British English; analogs is typical in American English.

In chemistry and pharmacology, a chemical analogue is a compound that shares a core chemical framework with another substance but differs in atoms or functional groups. Analogs are used to explore structure–activity relationships and to optimize properties such as potency, selectivity, or metabolic stability. Examples include various homologous series of benzenoid compounds and drug analogues designed to improve pharmacokinetics.

In biology, analogous structures are features that perform similar functions in different lineages but arose independently. These analogues illustrate convergent evolution and contrast with homologous structures, which reflect common ancestry. Examples include wings of birds and insects, or the camera-type eyes of cephalopods and vertebrates.

In linguistics, analogues emerge through analogy, a cognitive process that regularizes irregular forms or extends patterns to new words. Analogical change can produce analogues that share paradigmatic forms across languages.

In technology and measurement, analogue (British English) or analog (American English) is used to describe continuous signals or devices that preserve a range of values, as opposed to digital representations.

The term derives from Greek analogos, meaning proportion or correspondence, from ana- 'again' and logos 'ratio'.