如果生词是句子或段落所解释的定义，理解句子或段落本身就是推断词义。
例如： anthropology is the scientific study of man. 由定义可知，anthropology就是“研究人类的科学”。
In slang the term "jam" constitutes a state of being in which a person finds himself or herself in a difficult situation. 同样，从上下文的定义可知jam一词在俚语中的意思是“困境”。 定义句的谓语动词多为：be, mean, deal with, be considered, to be, refer to, be called, be known as, define, represent, signify, constitute等。
2. 根据复述猜测词义
虽然复述不如定义那样严谨、详细，但是提供的信息足以使阅读者猜出生词词义。 复述部分可以适当词、短语或是从句。
同位语 Semantics, the study of the meaning of words, is necessary if you are to speak and read intelligently.
此例逗号中短语意为“对词意义进行研究的学科”。该短语与前面生词semanties式同位关系，因此我们不难猜出semanties指“语义学”。
在复述中构成同位关系的两部分之间多用逗号连接，有时也使用破折号，冒号，分 号，引号，和括号等。
Capacitance, or the ability to store electric charge, is one of the most common characteristics of electronic circuits.
由同位语我们很快猜出生词capacitance词义---电容量。
需要注意的是：同位语前 还常有or, similarly, that is to say, in other words, namely, or other, say i. e. 等副词或短语出现。
定语从句 Krabacber suffers from SAD, which is short for seasonal affective disorder, a syndrome characterized by severe seasonal mood swings.
根据生词SAD后面定语从句which is short for seasonal affective disorder和同位语a syndrome characterized by severe seasonal mood swings, 我们可以推断出 SAD含义，即“季节性情绪紊乱症”。
3. 根据举例猜测词义
恰当的举例能够提供猜测生词的重要线索，例如：
The consequences of epochal events such as wars and great scientific discoveries are not confined to a small geographical area as they were in the past. 句中“战争”和“重大科学发现”是生词的实例，通过它们我们可以猜出epochal的大致词义“重要的”，这与其确切含义“划时代的”十分接近。
