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In linguistics and related fields, an emic unit is a type of abstract object. Kinds of emic units are generally denoted by terms with the suffix -eme, such as phoneme, grapheme, and morpheme. The term "emic unit" is defined by Nöth (1995) to mean "an invariant form obtained from the reduction of a class of variant forms to a limited number of abstract units". The variant forms are called etic units (from phonetic). This means that a given emic unit is considered to be a single underlying object that may have a number of different observable "surface" representations.
The first emic unit to be considered, in the late 19th century, was the phoneme. The word phoneme comes from the Greek: φώνημα, phōnēma, meaning "that which is sounded", from the verb φωνέω, phōneō, "sound", which comes in turn from the noun φωνή, phōnē, "sound". Thus it was originally used (in its French form phonème) to refer simply to a speech sound. But it soon came to be used in its modern sense, to denote an abstract concept (for more details, see Phoneme: Background and related ideas). It is by analogy with phoneme that other emic units, such as the morpheme and the grapheme, were named using the -eme suffix. The actual terms "emic unit" and "etic unit" were introduced by Kenneth Pike (1954).
The prefix allo- used in terms such as allophone is from the Ancient Greek ἄλλος meaning "other". The prefix is also used in chemistry.
The following are the most commonly analyzed kinds of emic units in linguistics:
In linguistics a distinction is made between so-called "emic" and "etic" accounts. For example a phonemic description is one expressed in terms of phonemes, whereas a phonetic one is based on the phones actually produced. This distinction was generalized by Pike (1954) and is applied in various social and behavioral sciences. In this general sense, an emic account is one that assumes insider knowledge of a phenomenon (as for example the unconscious awareness of a language's phonemic system that is assumed to be possessed by that language's native speakers). By contrast, an etic account is one based on the observations of an outsider.