Abstract
This paper introduces cognitive linguistics at first. After a compassion of two traditional methods in dictionary compiling and their shortages, it is proposed that  applying cognitive theories of metaphor and metonymy into dictionary compiling will enlarge learner's vocabulary and help them in memorizing word meanings. Core part of this study is the introduction of metaphor and metonymy theories into the analysis of polysemous words in English dictionary.
Keywords   metaphor theory   metonymy theory   polysemous words dictionary compiling

本文首先介绍了认知语言学理论，然后分析了传统词典编纂的历史原则和频率原则的各自特点以及不足之处，提出利用隐喻理论和转喻理论来编纂词典对英语学习者的词汇拓展有很多优势，同时也有利于英语学习者对词汇的释义进行记忆，本文的核心是介绍隐喻理论和转喻理论,并进一步阐述了隐喻理论和转喻理论对多义词释义编纂的优势。
关键词  隐喻理论  转喻理论  多义词 词目释义

1. Introduction
1.1 Dictionary and dictionary definition
According to Webster's New World College Dictionary (Fourth Edition, 2002), a dictionary, also referred to as a lexicon, wordbook, or vocabulary, is a collection of words in one or more specific languages, often listed alphabetically, with usage information, definitions, etymologies, phonetics, pronunciations, and other information; or a book of words in one language with their equivalents in another, also known as a lexicon. A dictionary may be regarded as a lexicographical product that is characterized by three significant features: (1) it has been prepared for one or more functions; (2) it contains data that have been selected for the purpose of fulfilling those functions; and (3) its lexicographic structures link and establish relationships between the data so that they can meet the needs of users and fulfill the functions of the dictionary (Nelson, 2008: 170).
The function of a dictionary is to contain a collection of words and definitions in some definite orders. The most important part of a dictionary is the definitions of words. People learn vocabulary for the purpose of being more accurate in using language and to exchange information in daily life. Nowadays, historical principle and frequency principle are two main methods used in dictionary definition order. But they fail to reflect the cognitive relationship between definitions of a given word. However, the cognitive linguistics rises from 1980s provides lexicographers the possibility of sorting definition orders based on their cognitive relationship. The theories of categorization, metaphor and metonymy explain the evolvement of word definitions from a prototypical meaning to other extended meaning.