allos

Allos is the transliteration of the Ancient Greek word ἄλλος, meaning “other” or “another.” In classical texts it appeared as an independent adjective, but in modern scholarly and scientific terminology it is most often used as a combining form to indicate contrast or difference from what is self or usual.

In taxonomy and paleontology, the root appears in genus and species names that convey a sense of “different” or “distinct.” A well-known example is Allosaurus, a theropod dinosaur whose name translates to “other lizard.” The designation reflects naming practices that distinguish a creature from related forms rather than making a literal description of its appearance.

In modern science and medicine, allo- is a productive prefix derived from ἄλλος. It signals a relationship to something “other” in contrast to “auto-” (self). Common examples include allogeneic (originating from a different individual of the same species), allograft (a graft from a donor), and allosteric (regarding a site other than the primary active site in a molecule). The prefix also appears in terms such as allopathy, alloplastic, and allostatic, where the root conveys the idea of difference or alteration relative to a reference standard.

Overview and usage note: Allos functions primarily as a linguistic and technical marker rather than as a standalone concept. It is widely used across biology, medicine, chemistry, and taxonomy to denote “other” or “different,” distinguishing processes or entities from self-referential or identical counterparts.

See also: prefixes in scientific terminology, allo- in biology and chemistry, Allosaurus.