ONE major word-formation process in English is to use the noun itself as a verb to express the action conveyed or implied by the noun, but without changing in any way the form of the noun. This direct noun-to-verb conversion, which has been taking place since language began, has given English such basic action verbs as 'eye' for 'to watch or study closely,' 'nose' for 'to search impertinently,' 'face' for 'to deal with straightforwardly,' and 'stomach' for 'to bear without overt resentment.'

So rather than come up with a new word for the action that a body part typically can do literally or figuratively, the early English speakers simply made that body part stand for the action itself and later on for tools, machines, and technologies themselves. By this process, an estimated one-fifth of all English verbs had been formed from nouns.