在古英语中,out(副词)常用作前缀,搭配名词、形容词、副词和动词,表示“向外、外部、外面的;向前、离开”。这种用法在中英语中更为普遍,涵盖了“外部、外面、从外部、外在、完全、彻底、极其”等多种含义。out 作为前缀的其他引申义包括“超出表面或界限、达到极限、明确的解决方案”等。
In composition out has either its ordinary adverbial sense, as in outcast, outcome, outlook, etc., or a prepositional force, as in outdoors, or forms transitive verbs denoting a going beyond or surpassing of the object of the verb, in doing the act expressed by the word to which it is prefixed, as in outrun, outshine, outvenom, etc. In the last use especially out may be used with almost any noun or verb. [Century Dictionary]
在构词中,out 可以保留其普通的副词意义,如 outcast, outcome, outlook 等,也可以作为介词使用,如 outdoors。此外,它还可以构成及物动词,表示超越或超过动词所指对象的动作,意为“在做某事时超越其本身”,例如 outrun, outshine, outvenom 等。在这种用法中,out 几乎可以与任何名词或动词搭配使用。[世纪词典]