2018考研同学应英语掌握5500左右的词汇以及相关词组。下面新东方在线为2018考研同学整理了一些词汇，除掌握词汇的基本含义外，考生还应掌握词汇之间的词义关系以及词汇之间的搭配关系，掌握词汇生成的基本知识。
1. degenerate
adj. 退化的;堕落的;变质的;变性的;
vt. 使退化;恶化;使变质;衰减;
vi. 退化;堕落;
[例句]Inactivity can make your joints stiff, and the bones may begin to degenerate.
长期不活动会导致关节僵硬，骨骼也可能开始退化。
2. deduce
vt. 演绎;推论，推断;追溯根源;
[例句]Alison had cleverly deduced that I was the author of the letter.
艾莉森已经聪明地推断出那封信就是我写的。
3. define
vt. 规定;使明确;精确地解释;画出…的线条;
vi. (给词、短语等)下定义，构成释义;
[例句]We were unable to define what exactly was wrong with him.
我们说不清楚他到底哪里不对劲。
4. deliver
vt. 交付;发表;递送;使分娩;
vi. 传送;投递;
[例句]The Canadians plan to deliver more food to southern Somalia.
加拿大计划向索马里南部地区运送更多的食品。
5. demonstrate
vt. 论证;证明，证实;显示，展示;演示，说明;
vi. 示威游行;
[例句]The study also demonstrated a direct link between obesity and mortality.
该研究还表明了肥胖症和死亡率之间存在直接的联系。
6. deviate
v. 脱离，越轨，违背，误入歧途;使脱离常轨;
[例句]They stopped you as soon as you deviated from the script.
一旦你偏离了剧本的内容，他们就会喊停。
7. devote
vt. 奉献;把…奉献(给)，把…专用(于);
[例句]He decided to devote the rest of his life to scientific investigation.
他决定将自己的余生献给科学研究事业。
8. diagnose
vt. 诊断;判断;
vi. 做出诊断;
[例句]The soldiers were diagnosed as having flu.
这些士兵经诊断患了流感。
9. dictate
vt. 口述;命令，指示;使听写;控制，支配;
vi. 口述;命令;
n. 命令;指示;指导原则;
[例句]Sheldon writes every day of the week, dictating his novels in the morning.
谢尔登一周7天都要写作，每天早上口述小说让别人记录。
10. differentiate
v. 区分，区别，辨别;
vt. 表明…间的差别，构成…间差别的特征;[数学]求…的微分：计算导数或(函数的)微分;
[例句]At this age your baby cannot differentiate one person from another.
这个年龄的婴儿还不能认人。