Back-formation in the context of "Anamniotes"

The Homeridae (Ancient Greek: Ὁμηρίδαι) were a family, clan or professional lineage on the island of Chios claiming descent from the Greek epic poet Homer.

The origin of the name seems obvious: in classical Greek the word should mean "children of Homer". An analogous name, Asclepiadae, identified a clan or guild of medical practitioners as "children of Asclepius". However, since the existence of the Homeridae is authenticated while that of Homer is not, and since Greek homeros is a common noun meaning "hostage", it was suggested even in ancient times that the Homeridae were in reality "children (or descendants) of hostages". The natural further step is to argue that Homer, the supposed founder, is a mythical figure, a mere back-formation, deriving his name from that of the later guild.

In biology, the taxon (back-formation from taxonomy; pl.: taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based ("Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping.

Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle and, later still, European scientists, like Magnol, Tournefort and Carl Linnaeus's system in Systema Naturae, 10th edition (1758),, as well as an unpublished work by Bernard and Antoine Laurent de Jussieu, contributed to this field. The idea of a unit-based system of biological classification was first made widely available in 1805 in the introduction to Jean-Baptiste Lamarck's Flore françoise, and Augustin Pyramus de Candolle's Principes élémentaires de botanique. Lamarck set out a system for the "natural classification" of plants. Since then, systematists continue to construct accurate classifications encompassing the diversity of life; today, a "good" or "useful" taxon is commonly taken to be one that reflects evolutionary relationships.

In linguistics, clipping, also called truncation or shortening, is word formation by removing some segments of an existing word to create a diminutive word or a clipped compound. Clipping differs from abbreviation, which is based on a shortening of the written, rather than the spoken, form of an existing word or phrase. Clipping is also different from back-formation, which proceeds by (pseudo-)morpheme rather than segment, and where the new word may differ in sense and word class from its source. In English, clipping may extend to contraction, which mostly involves the elision of a vowel that is replaced by an apostrophe in writing.

In morphology and syntax, a clitic (/ˈklɪtɪk/ KLIT-ik, backformed from Greek ἐγκλιτικός enklitikós "leaning" or "enclitic") is a morpheme that has syntactic characteristics of a word, but depends phonologically on another word or phrase. In this sense, it is syntactically independent but phonologically dependent—always attached to a host. A clitic is pronounced like an affix, but plays a syntactic role at the phrase level. In other words, clitics have the form of affixes, but the distribution of function words.

Clitics can belong to any grammatical category, although they are commonly pronouns, determiners, or adpositions. Note that orthography is not always a good guide for distinguishing clitics from affixes: clitics may be written as separate words, but sometimes they are joined to the word they depend on (like the Latin clitic -que, meaning "and") or separated by special characters such as hyphens or apostrophes (like the English clitic 's in "it's" for "it has" or "it is").

Aegea is a back-formation from "Aegean", the sea that was named after an eponymous Aegeus in early levels of Greek mythology. The Encyclopædia Britannica (1911) mentioned an Aegea, queen of the Amazons, as an alternative eponym of the Aegean Sea. Legend says she commanded an army of Amazon women warriors that traveled from Libya to Asia Minor to fight at Troy, and that she perished at sea with her army.

Modern Italian has the adjective Egea ("Aegean"), but Classical Latin had none. Modern botanical Latin sometimes uses the specific epithet aegea to mean "of the Aegean".