In linguistics, conversion, also called zero derivation or null derivation, is a kind of word formation involving the creation of a word (of a new word class) from an existing word (of a different word class) without any change in form, which is to say, derivation using only zero. For example, the noun green in golf (referring to a putting-green) is derived ultimately from the adjective green. Conversions from adjectives to nouns and vice versa are both very common and unnotable in English; much more remarked upon is the creation of a verb by converting a noun or other word (e.g., the adjective clean becomes the verb to clean). Verbification Verbification, or verbing, is the creation of a verb from a noun, adjective or other word. In English In English, verbification typically involves simple conversion of a non-verb to a verb. The verbs to verbify and to verb, the first by derivation with an affix and the second by zero derivation, are themselves products of verbification (see autological word), and, as might be guessed, the term to verb is often used more specifically, to refer only to verbification that does not involve a change in form. (Verbing in this specific sense is therefore a kind of anthimeria.) Examples of verbification in the English language number in the thousands, including some of the most common words such as mail and e-mail, strike, talk, salt, pepper, switch, bed, sleep, ship, train, stop, drink, cup, lure, mutter, dress, dizzy, divorce, fool, merge, to be found on virtually every page in the dictionary. Thus, verbification is by no means confined to slang and has furnished English with countless new expressions: "access", as in "access the file", which was previously only a noun, as in "gain access to the file". Similar mainstream examples include "host", as in "host a party", and "chair", as in "chair the meeting". Other formations, such as "gift", are less widespread but nevertheless mainstream. Verbification may have a bad reputation with some English users because it is such a potent source of neologisms. Although some neologistic products of verbification may meet considerable opposition from prescriptivist authorities (the verb sense of impact is a well-known example), most such derivations have become so central to the language after several centuries of use that they no longer draw notice. In many cases, the verbs were distinct from their noun counterparts in Old English, and