推測詞義是應用英語的重要能力，也是考試有的題型。它不但需要準確無誤地理解上下文，而且要有較大的泛讀量，掌握或認識較多的課外詞匯，學會順藤摸瓜，通過構詞、語法、定義、同位、對比、因果、常識、上下文等線索確定詞義。下面介紹幾種猜詞的方法:
①定義法，即通過文章中對生詞的定義確定其詞義，如:
Annealing is a way of making metal softer by heating it and then letting it cool very slowly.
句子給予annealing 以明確的定義，即"退火"。再如:
It will be very hard but also very brittle-that is, it will break easily.
從后面的解釋中我們可以了解到brittle 是"脆的、容易折斷的"意思。又如: The herdsman, who looks after sheep, earns about 650 yuan a year.
定語從句中 looks after sheep表明了herdsman 的詞義為"牧羊人"。
②同位法，即通過句子中的同位成分如同位語、同位語從句、破折號后的詞組或語句來確定詞義, 如: They traveled a long way, at last got to a castle, a large building in old times.
同位語部分a large building in old times 給出了 castle 的確切詞義，即"城堡"。
We are on the night shift-from midnight to 8 a.m.-this week.
兩個破折號之間的短語很清楚地表明night shift 是"夜班"的意思。
③對比法，即通過同義、反義或轉(zhuǎn)折詞的關系來確定詞義, 如:
She is usually prompt for all her class, but today she arrived in the middle of her first class.
but一詞表轉(zhuǎn)折，因此but 前后的意思正相反。后半句的意思是她今天"第一節(jié)上了一半才來"，因此反向推理，可得出她平時一向"準時"的結(jié)論。
④構詞法（前綴、后綴、復合、派生等），即運用詞根、詞綴的意義判斷詞義，如:
Perhaps, we can see some possibilities for next fifty years. But the next hundred?
possibility 是 possible 的同根名詞，據(jù)此可以判斷定 possibility 意思是"可能性"。
⑤因果法，即運用因果關系和因果詞如so, because, therefore, hence等來判斷詞義，如:
The lack of movement caused the muscles to weaken. Sometimes the weakness was permanent. So the player could never play the sport again.
從后面的結(jié)果"永遠不能再運動"中，可以推測 permanent 的意思為"永遠的，永久的"。
①定義法，即通過文章中對生詞的定義確定其詞義，如:
Annealing is a way of making metal softer by heating it and then letting it cool very slowly.
句子給予annealing 以明確的定義，即"退火"。再如:
It will be very hard but also very brittle-that is, it will break easily.
從后面的解釋中我們可以了解到brittle 是"脆的、容易折斷的"意思。又如: The herdsman, who looks after sheep, earns about 650 yuan a year.
定語從句中 looks after sheep表明了herdsman 的詞義為"牧羊人"。
②同位法，即通過句子中的同位成分如同位語、同位語從句、破折號后的詞組或語句來確定詞義, 如: They traveled a long way, at last got to a castle, a large building in old times.
同位語部分a large building in old times 給出了 castle 的確切詞義，即"城堡"。
We are on the night shift-from midnight to 8 a.m.-this week.
兩個破折號之間的短語很清楚地表明night shift 是"夜班"的意思。
③對比法，即通過同義、反義或轉(zhuǎn)折詞的關系來確定詞義, 如:
She is usually prompt for all her class, but today she arrived in the middle of her first class.
but一詞表轉(zhuǎn)折，因此but 前后的意思正相反。后半句的意思是她今天"第一節(jié)上了一半才來"，因此反向推理，可得出她平時一向"準時"的結(jié)論。
④構詞法（前綴、后綴、復合、派生等），即運用詞根、詞綴的意義判斷詞義，如:
Perhaps, we can see some possibilities for next fifty years. But the next hundred?
possibility 是 possible 的同根名詞，據(jù)此可以判斷定 possibility 意思是"可能性"。
⑤因果法，即運用因果關系和因果詞如so, because, therefore, hence等來判斷詞義，如:
The lack of movement caused the muscles to weaken. Sometimes the weakness was permanent. So the player could never play the sport again.
從后面的結(jié)果"永遠不能再運動"中，可以推測 permanent 的意思為"永遠的，永久的"。