Isonym

The suffix -onym, in English and other languages, means "word, name", and words ending in -onym refer to a specified kind of name or word, most of which are classical compounds. For example, an acronym is a word formed from the initial letter or letters of each of the successive parts or major parts of a compound term (as radar). The use of -onym words provides a means of classifying, often to a fine degree of resolution, sets of nouns with common attributes.

In some words, the -onym form has been modified by replacing (or dropping) the "o". In the examples ananym and metanym, the correct forms (anonym and metonym) were pre-occupied by other meanings. Other, late 20th century examples, such as hypernym and characternym, are typically incorrectly formed neologisms for which there are more traditional words formed in -onym (hyperonym and charactonym).

The English suffix -onym is from the Ancient Greek suffix -ώνυμον (ōnymon), neuter of the suffix ώνυμος (ōnymos), having a specified kind of name, from the Greek ὄνομα (ónoma), Aeolic Greek ὄνυμα (ónyma), "name". The form -ōnymos is that taken by ónoma when it is the end component of a bahuvrihi compound, but in English its use is extended to tatpurusa compounds.

The suffix is found in many modern languages with various spellings. Examples are: Dutch synoniem, German Synonym, Portuguese sinónimo, Russian синоним (sinonim), Polish synonim, Finnish synonyymi, Indonesian sinonim.

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