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English definition of “prefix”

prefix

noun [C] (GRAMMAR)    /ˈpriː.fɪks/
B2 a letter or group of letters added to the beginning of a word to make a new word: In the word 'unimportant', 'un-' is a prefix. → See also affix nounMorphology and parts of words affix nounGrammar:PrefixesPrefixes are letters which we add to the beginning of a word to make a new word with a different meaning. Prefixes can, for example, create a new word opposite in meaning to the word the prefix is attached to. They can also make a word negative or express relations of time, place or manner. Here are some examples:See moreGrammar:Word formationThere are four main kinds of word formation: prefixes, suffixes, conversion and compounds.See moreGrammar:PrefixesWe add prefixes before the base or stem of a word.See moreGrammar:SuffixesWe add suffixes after the base or stem of a word. The main purpose of a suffix is to show what class of word it is (e.g. noun or adjective).See moreGrammar:ConversionConversion involves the change of a word from one word class to another. For example, the verbs to email and to microwave are formed from the nouns email and microwave:See moreGrammar:CompoundingWhen we use compounding, we link together two or more bases to create a new word. Normally, the first item identifies a key feature of the second word. For example, the two bases back and ache can combine to form the compound noun backache, and the two bases post and card combine to form the compound noun postcard.See moreGrammar:AbbreviationAbbreviation involves shortening a word. We do this in three main ways: clipping, acronyms and blends.See moreGrammar:Back-formationWe form words with back-formation when we remove part of a word, usually something which we think is a suffix (or occasionally a prefix). We do this commonly when we form verbs from nouns.See more
(Definition of prefix noun (GRAMMAR) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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