英语词汇意义大多有本义（denotation）和转义（connotation）之分。本义就是：the direct, explicit meaning or reference of a word or term（Webster’s New World Dictionary, p.368），意即词语的直接显豁的意义或指示意义。例如library一词的本义是：a place where books may be read or borrowed。而转义则是指：idea or notion suggested by or associated with a word, phrase, etc. in addition to its explicit meaning…（Ibid, p.295）简言之，它是指一个词除显豁的本义之外引起人们联想、反应等的引申意义，又称涵义。换言之，如果具有本义的library被用于特定的上下文，便可产生特定的涵义。从本义到转义是一重要而常见的英语措辞技巧或修辞手法。请看例句：

1/ The library is the storehouse of human knowledge and aspiration.

2/ He was a boring person because all he had was library knowledge.

句1中library的涵义显而易见，在读者脑中能引起褒义的联想，而句2中的“library”则有“呆板”（stuffiness）、“狭隘”（confinement）等涵义。又如：

1/ These orphans need somebody to mother them. The old lady mothered him during his illness.

2/ I resent being mothered. The boy is spoiled because you have been mothering him.

mother的本义是female parent，它的转义一般都是emotional warmth、comfort、security等。在上述两种特定的上下文里，mother一词虽然都用作动词，但涵义却各自有别。在句1中意为take good care of，在句2中却转为overprotect。

其实，在日常说话或写作时，有许多情况看似属于选词不当，但实际上是因为不注意词汇的转义而导致的误用。例如，假使你对一个姑娘说“You are thin.”这是客观描述。但如果对她说“You are skinny.”恐怕会得罪她。要是你改说“You are slim（or slender）”，她就会十分高兴。究其原因，thin、skinny、slender、slim等词的本义都是below the average weight，但它们各自辐射出的涵义（即转义）却相去甚远。所以在语言交际中，我们应特别注意所使用的词的涵义。

下面让我们看几个因不注意词汇的转义而导致选词不当的实例：

1/ I was overcome with grief because my old man had kicked the bucket.

句中的old man虽有father的本义，kick the bucket也有die的本义，但old man给人以不敬之感，kick the bucket更有不严肃、不庄重之嫌，实属选词不当。

2/ Some of my classmates wanted to be scientists, writers or teachers. Some wanted to be physicians or nurses. And some others wanted to be politicians.

Politician和statesman的本义虽然都是a person interested in politics，但politician的转义常指someone who engages in politics for his own selfish purposes。试问，有哪位同学会有如此理想呢？

3/ My aunt is a generous and charitable woman; she is very pious in her desire to help others.

此句作者显然忽视了pious一词在这一上下文中可能使读者产生的联想意义。pious通常只用于宗教信仰，意指devotion in religion。如果用于非宗教事物，不如改用self-righteous。

4/ I was especially grateful to Professor Collins, for his course in modern arts indoctrinated me in the techniques of modern painting.

句中的indoctrinate虽和teach本义相同，却会令读者产生propaganda、forced instruction之类的联想，应予以避免。

5/ The teachers all praised Xiao Lei for she was really a grind.

grind一词虽有“用功的学生”之意，但常转义为“过分用功的书呆子”，不如改用diligent student或hardworking student。